DAVID R. DALTON - Academia.edu (original) (raw)

Papers by DAVID R. DALTON

Research paper thumbnail of Surface-Catalyzed Reaction between the Gases Hydrogen Chloride and Isoprene

ACS Earth and Space Chemistry, 2017

Mixtures of gaseous hydrogen chloride (38−150 Torr) and isoprene (38−80 Torr) were allowed to rea... more Mixtures of gaseous hydrogen chloride (38−150 Torr) and isoprene (38−80 Torr) were allowed to react in Pyrex IR cells equipped with sodium chloride windows. The disappearance of reactants to form, initially, 3-chloro-3-methyl-1-butene and 1-chloro-3-methyl-2-butene was monitored and subsequent formation of multimeric products, some of which were brown, were observed. Such products may contribute to the formation of, or be found on, atmospheric particles.

Research paper thumbnail of Syntheses of Morphine and Codeine (1992‐2002): Templates for Exploration of Synthetic Tools

ChemInform, 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Research paper thumbnail of The uncatalyzed gas phase hydrochlorination of alkenes I. Propene and isobutylene

Tetrahedron Letters, 1974

Research paper thumbnail of Hindered rotation in 1-benzyl-1,2,3,4-tetrahydro-6,7-dimethoxyisoquinolines

Tetrahedron Letters, 1965

Research paper thumbnail of Gas phase surface-catalyzed HCl addition to vinylacetylene: motion along a catalytic surface. Experiment and theory

Tetrahedron, 2008

Gaseous mixtures of HCl and vinylacetylene were permitted to react in Pyrex IR cells (NaCl window... more Gaseous mixtures of HCl and vinylacetylene were permitted to react in Pyrex IR cells (NaCl windows). Gaseous 4-chloro-1,2-butadiene and 2-chloro-1,3-butadiene (chloroprene) were the major products. Kinetic data (FTIR) generated a rate expression in concert with surface catalysis. Computational studies involving surface associated water provide a view that accounts for the experimentally determined orders and a bifurcated pathway producing both products. The results are in accord with wall-adsorbed reactant(s) as well as previously reported computational studies on the reactants.

Research paper thumbnail of Nonsymmetric 9-Phenanthrylamines. An Improved Synthetic Procedure to a Useful Synthon

Synthetic Communications, 1976

... TO A USEFUL SYNTHON * Grant Krow , Kalyani M. Damodaran, Edward Michener, Stephen I. Miller a... more ... TO A USEFUL SYNTHON * Grant Krow , Kalyani M. Damodaran, Edward Michener, Stephen I. Miller and David R. Dalton Department of Chemistry, Temple University, Philadelphia ... (b) P. Hugelshofer, J. Kalvoda and K. Shaffner, Helv. aim. ... (b) SI Miller, Ph.D. Thesis, Temple ...

Research paper thumbnail of Bromohydrin formation in dimethyl sulfoxide

Journal of the American Chemical Society, 1968

The spectrometer was purchased from funds provided by a grant (CAO8841) from the National Cancer ... more The spectrometer was purchased from funds provided by a grant (CAO8841) from the National Cancer Institute, National Institutes of Health. We gratefully acknowledge this financial assistance. (20) H. 0. House, J. Amer. Chem. SOC., 77, 3070 (1955). (21) By comparison with mixtures of known composition, less than (22) A

Research paper thumbnail of Hindered rotation in substituted 1,2,3,4-tetrahydro-6,7-dimethoxyisoquinolines

Journal of the American Chemical Society, 1969

Conformational information concerning 1-and 2-substituted 1,2,3,4-tetrahydro-6,7-dimethoxyisoquin... more Conformational information concerning 1-and 2-substituted 1,2,3,4-tetrahydro-6,7-dimethoxyisoquinolines can be obtained by examination of the proton magnetic resonance (pmr) spectra of a suitable series of these compounds. The pmr spectra of 1,2,3,4-tetrahydro-2-acetyl-6,7-dimethoxyisoquinoline and its C-1 derivatives indicate the presence of unequal populations of two conformers at room temperature. The rates of exchange between the conformers were, in several cases, obtained from a match of experimental line widths (expanded sweeps) and calculated line widths as derived from the Gutowsky-Holm line shape equation. In the case of l-benzyl-2-acetyl-l,2,3,4-tetrahydro-6,7-dimethoxyisoquinoline the rates were obtained from the methoxy, acetyl, and aromatic resonances and each gave Arrhenius activation energies of 20.6 f 0.5 kcal/mole. The collective data for this series suggest that the two conformations observed reflect the two minimum energy conformations of N,N-disubstituted amides resulting from rotation of the N-acetyl group. This conclusion, as well as that concerning the value of the activation energy for the exchange process, differs markedly from that previously reached. Finally, in 2substituted 1-(o-aminobenzyl)-l,2,3,4-tetrahydro-6,7-dimethoxyisoquinolines, the location of the C-1 benzyl group appears to be a function of the size of the substituent in the 2 position.

Research paper thumbnail of Gas phase addition of hydrogen chloride to propylene

Journal of the American Chemical Society, 1975

Page 1. 5614 Chem. Soc., 94, 8934 (1972): (b) RJ Blint, TB McMahon. and JL Beauchamp, ibid., 96, ... more Page 1. 5614 Chem. Soc., 94, 8934 (1972): (b) RJ Blint, TB McMahon. and JL Beauchamp, ibid., 96, 1269 (1974). (2) JHJ Dawson. WG Henderson, RM D'Maliey, and KR Jennings, Int. J. Mass Spectrom. /on Phys., 11, 61 (1973). ...

Research paper thumbnail of Electron spin resonance studies on neutral aromatic hydrocarbon radicals

Journal of the American Chemical Society, 1969

Nmr Measurements. The pmr spectra were taken with a Varian HA-100 and an A-60A (or A-60) spectrom... more Nmr Measurements. The pmr spectra were taken with a Varian HA-100 and an A-60A (or A-60) spectrometers in about 10% solutions in D,O containing DSS as an internal reference at various temperatures. The lH,lH double-resonance experiments were carried out by using the HA-100 spectrometer operating at 100 MHz in the frequency-swept and DSS-locked mode with a Hewlett-Packard HP-200ABR audiooscillator. The peak positions were calibrated by direct readings of frequencies using a Hewlett-Packard HP-5212A electronic counter with accuracies to 50.1 Hz. The spectra taken with the A-60A (or A-60) spectrometer were calibrated by the usual side-band method. The lH,I*N double-resonance spectra of I and 111 at 100 MHz were recorded on the Varian HA-100 spectrometer equipped with an NMR Specialties HD-60B heteronuclear lH,l4N spin decoupler operating at about 7.224 MHz. All the spectra were taken in the frequency-swept and DSS-locked mode. The modulation frequencies were directly read by using the HP-5212A electronic counter. The lH,14N double-resonance spectrum of I at 60 MHz was measured with the Varian A-60 spectrometer equipped with an NMR Specialties HD-60A heteronuclear IH,I4N spin decoupler operating at about 4.33 MHz. The 14N nmr spectrum of I was determined with a Spectrospin AG (Zurich) HX-3 spectrometer at a frequency of 6.50 MHz (a field of about 21 kG) with simultaneous field-frequency locking on the N+(CH& proton resonance and 1H,14N decoupling of the CHB protons. The spectrometer was operated in the frequency-swept mode. The solution used was 3 0 x in DzO; the sample tube has 13 mm 0.d. Referencing was achieved by inserting a tube containing an acidified aqueous ammonium nitrate solution. Materials. Trimethylvinylammonium bromide (I) was commercially available. Trimethyl-(trans-pphenylviny1)ammonium bromide (11) was prepared according to Truce and SimmsS5l

Research paper thumbnail of Hindered Rotation in 1-Benzyl-1,2,3,4-tetrahydro-6-7-dimethoxyisoquinolines

Journal of the American Chemical Society, 1967

... Figures 3 and 4 depicit the aryl and acetyl resonances Fraenkel, Cava, Dalton 1 l-Benzyl-l,2,... more ... Figures 3 and 4 depicit the aryl and acetyl resonances Fraenkel, Cava, Dalton 1 l-Benzyl-l,2,3,4-tetrahydro-6,7-dimethoxyisoquinolines Page 4. ... Ber., 98, 2438 (1965); E. Vogel, W. A. Boll, and H. Gunther, Tetrahe-dron Letters, 609 (1965); JA Moore and J. Binkert, J. Am. ...

Research paper thumbnail of Decoration of the Aromatic Ring of Dihydrocodeinone (Hydrocodone) and 14-Hydroxydihydrocodeinone (Oxycodone)

The Journal of Organic Chemistry

Improved protocols for the preparation of 1-bromodihydrocodeinone (1-bromohydrocodone) and 1-brom... more Improved protocols for the preparation of 1-bromodihydrocodeinone (1-bromohydrocodone) and 1-bromo-14-hydroxydihydrocodeinone (1-bromooxycodone) and synthesis of the corresponding 1-chloro and 1-iodo derivatives have been achieved using the corresponding N-halosuccinimides in acidic milieu. The corresponding 1-carboethoxy derivative of 14-hydroxydihydrocodeinone (1-carboethoxyoxycodone) has been prepared by Pd-catalyzed reaction with carbon monoxide in ethanol. The ester was hydrolyzed to the corresponding zwitterionic amino acid.

Research paper thumbnail of The Dimethyl-p-dioxanes and the 2,5-Dibutyl-p-dioxanes

The Journal of Organic Chemistry, 1962

The isomeric dimethyl-p-dioxanes have been synthesized. Contrary to former reports, their boiling... more The isomeric dimethyl-p-dioxanes have been synthesized. Contrary to former reports, their boiling points are consistent with current theory. The boiling points of the 2,5-din -butyl-p-dioxanes are anomalous. helpful discussion and for loan of facilities while this manuscript was in preparation.

Research paper thumbnail of A New Isoquinuclidine Synthesis. A New Route to dl-Dioscorone 1

The Journal of Organic Chemistry, 1965

The Diels-Alder addition of l,&cyclohexadiene to methyleneurethan (generated in situ) yields 2-ca... more The Diels-Alder addition of l,&cyclohexadiene to methyleneurethan (generated in situ) yields 2-carbethoxy-2-azabicyclo [2.2.2]oct-5-ene (VII). The latter ester has been converted into isoquinuclidine (2-azabicyclo-[2,2.2]octanel I) and, in several steps, into dZ-dioscorone (IV).

Research paper thumbnail of MM2 force field parameters for oximes

The Journal of Organic Chemistry, 1988

The MM2 force field method has been extended to include oximes. Necessary parameters have been de... more The MM2 force field method has been extended to include oximes. Necessary parameters have been developed by using formaldoxime, (E)and (2)-acetaldoxime, a n d acetone oxime. The "methylene tilt" of formaldoxime has been successfully reproduced and calculated rotational barriers, moments of inertia, and dipole moments are in good agreement with the available experimental data.

Research paper thumbnail of Hofmann degradation of .beta.-hydroxy ammonium salts. II. 4-Hydroxybenzylisoquinolines and 4-hydroxyaporphines

The Journal of Organic Chemistry, 1987

Experimental Section IR spectra were recorded on a JASCO A-3 spectrophotometer. 'H NMR spectra we... more Experimental Section IR spectra were recorded on a JASCO A-3 spectrophotometer. 'H NMR spectra were recorded on a JEOL JNM-FX 90 Q (90 MHz) spectrometer in CDCl,, and chemical shifts are expressed in 6 values relation to Me4Si as internal standard. Coupling constants (4 are given in hertz. Mass spectra were obtained on a JEOL JMS-DX 300 instrument. GLPC analyses were performed on a JEOL JGC-2OK instrument with a 10% SE-30 column (1 m X 3 mm). Microanalyses were performed by the Microanalytical Laboratory in this institute. 2-Isopropylcyclohexanone (3).7 A mixture of 2-isopropylphenol (2) (3.0 g, 22 mmol) and Raney nickel (W-2,0.5 mL, 300 mg)I8 in ethanol (15 mL) was hydrogenated (initial pressure of H2 at 20 "C, 110 lb) in an externally heated stainless-steel autoclave at 100 "C for 4 h. The catalyst was removed by filtration through a pad of Celite, and the filtrate was diluted with ether and washed successively with 5% aqueous NaOH, water, and saturated brine. Evaporation of the solvent left an oil, an epimeric mixture of 2-isopropylcyclohexanols, which was submitted to the following oxidation without purification. To a cold solution of the crude cyclohexanols in acetic acid (23 mL) was added a 10% aqueous sodium hypochlorite solutions (19.8 mL, 26.5 mmol) in an ice bath and the mixture was further stirred for 1.5 h in the cold. The reaction mixture was poured into cold water and extracted with ether. The ether extract was successively washed with aqueous NaHC03, aqueous NaHSO,, water, and saturated brine. Removal of the solvent gave an oil, which was distilled under reduced pressure to give 3.01 g (97%) of 3: bp 82 "C (12 mmHg) [litS7" bp 90-98 "C (30 mmHg)]; IR (neat) 1708, 1370 cm-'; 'H NMR 0.89 (d, 6 H, J = 7), 1.2-2.4 (m, 10 H). l-Hydroxy-c-2-isopropyl-r-l-cyclohexanecarbonitrile and Its 2-Epimer (4a and 4b). To a solution of 3 (362 mg, 2.58 mmol) in ethanol (3.6 mL) was added at 0 "C acetone cyanohydrin (1.65 mL, 18.2 mmol) and K&O, (107 mg, 0.77 mmol), and the mixture was further stirred at 0-10 "C for 18 h. The mixture was diluted with ether and washed with water and saturated brine. Removal of the solvent gave 4 as an isomeric mixture, which in general was submitted to the following ring expansion without separation. For characterization, however, these compounds were separated by flash column chromatography [silica gel, hexane-ethyl acetate (8:l) as solvent] to give 60 mg (14%) of 4b and 340 mg (79%) of 4a as

Research paper thumbnail of Enantioselective Synthesis of Aza Sugars from Amino Acids. 2.1 The 3-Hydroxy-2-hydroxymethylpyrrolidines2

The Journal of Organic Chemistry, 2001

... Qing Lu, ‡ Jessica Vey, ‡ § David R. Dalton,* ‡ and Patrick J. Carroll ¶. ... The results her... more ... Qing Lu, ‡ Jessica Vey, ‡ § David R. Dalton,* ‡ and Patrick J. Carroll ¶. ... The results here are in concert with his observations. (12) See, for example: Goulet, MT In Encyclopedia of Reagents for Organic Synthesis; Paquette, L., Ed.; John Wiley & Sons: New York: 1995, Vol. ...

Research paper thumbnail of Surface-catalyzed hydrochlorination of alkenes. The reaction of the gases hydrogen chloride and 1,3-butadiene

The Journal of Organic Chemistry, 1991

NH3), m/e 329 (M + la), 311 (M). An isomer of C&,CH2CH2CH(C&&H2CH(C&&I-bH4CN mass (CI, NH3) 433 (... more NH3), m/e 329 (M + la), 311 (M). An isomer of C&,CH2CH2CH(C&&H2CH(C&&I-bH4CN mass (CI, NH3) 433 (M + 18) (20), 415 M (15). Other unidentified products. Electrolysis of 4-Chlorobenzonitrile in Liquid Ammonia in t h e Presence of Catalyst (4,4'-Bipyridine, 10-2 M) (Experiment 2). The procedure was the same as above. Beyond the products described in Table I, the following product was indentified in one of the chromatographic fractions from its mass spectrum. C&5CH2CH2CH(C&6)CHOHC6H4CN m/e 327 (561, 222 (24), 130 (loo), 105 (97), 102 (85). Acknowledgment. We are grateful to N. Morin (Ecole Normale Supgrieure) for her help in mass spectroscopy analysis.

Research paper thumbnail of Hydrochlorination of alkenes. 3. Reaction of the gases hydrogen chloride and (E)- and (Z)-2-butene

The Journal of Organic Chemistry, 1986

... (3) Maass, 0.; Coffin, C. C. Can. J . Res. 1930, 3, 526, 533 and refer-ences therein. (4) (a)... more ... (3) Maass, 0.; Coffin, C. C. Can. J . Res. 1930, 3, 526, 533 and refer-ences therein. (4) (a) Brearley, D.; Kistiakowsky, G. B.; Stauffer, H. J. J. Am. Chem. SOC. 1936,58,43. (b) Kistiakowsky, G. B.;Stauffer, HC Ibid 1937,59, 165. (5) Haugh, M. J.; Dalton, D. R. J. Am. Chem. ...

Research paper thumbnail of A molecular mechanics study of amide conformations

The Journal of Organic Chemistry, 1989

The MM2 force field has been extended to include amides using experimentally known geometries for... more The MM2 force field has been extended to include amides using experimentally known geometries for formamide, acetamide, and their N-methyl derivatives in the parameterization. Relative stabilities of conformers, barriers to rotation, and dipole moments are reproduced within reported experimental error. Additionally, a conformational study of acylpiperidines was performed. Although primary and secondary amides are found to be planar or nearly so, use of the N-methyl derivatives in the parameterization results in a significant deviation from planarity for tertiary amides.

Research paper thumbnail of Surface-Catalyzed Reaction between the Gases Hydrogen Chloride and Isoprene

ACS Earth and Space Chemistry, 2017

Mixtures of gaseous hydrogen chloride (38−150 Torr) and isoprene (38−80 Torr) were allowed to rea... more Mixtures of gaseous hydrogen chloride (38−150 Torr) and isoprene (38−80 Torr) were allowed to react in Pyrex IR cells equipped with sodium chloride windows. The disappearance of reactants to form, initially, 3-chloro-3-methyl-1-butene and 1-chloro-3-methyl-2-butene was monitored and subsequent formation of multimeric products, some of which were brown, were observed. Such products may contribute to the formation of, or be found on, atmospheric particles.

Research paper thumbnail of Syntheses of Morphine and Codeine (1992‐2002): Templates for Exploration of Synthetic Tools

ChemInform, 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Research paper thumbnail of The uncatalyzed gas phase hydrochlorination of alkenes I. Propene and isobutylene

Tetrahedron Letters, 1974

Research paper thumbnail of Hindered rotation in 1-benzyl-1,2,3,4-tetrahydro-6,7-dimethoxyisoquinolines

Tetrahedron Letters, 1965

Research paper thumbnail of Gas phase surface-catalyzed HCl addition to vinylacetylene: motion along a catalytic surface. Experiment and theory

Tetrahedron, 2008

Gaseous mixtures of HCl and vinylacetylene were permitted to react in Pyrex IR cells (NaCl window... more Gaseous mixtures of HCl and vinylacetylene were permitted to react in Pyrex IR cells (NaCl windows). Gaseous 4-chloro-1,2-butadiene and 2-chloro-1,3-butadiene (chloroprene) were the major products. Kinetic data (FTIR) generated a rate expression in concert with surface catalysis. Computational studies involving surface associated water provide a view that accounts for the experimentally determined orders and a bifurcated pathway producing both products. The results are in accord with wall-adsorbed reactant(s) as well as previously reported computational studies on the reactants.

Research paper thumbnail of Nonsymmetric 9-Phenanthrylamines. An Improved Synthetic Procedure to a Useful Synthon

Synthetic Communications, 1976

... TO A USEFUL SYNTHON * Grant Krow , Kalyani M. Damodaran, Edward Michener, Stephen I. Miller a... more ... TO A USEFUL SYNTHON * Grant Krow , Kalyani M. Damodaran, Edward Michener, Stephen I. Miller and David R. Dalton Department of Chemistry, Temple University, Philadelphia ... (b) P. Hugelshofer, J. Kalvoda and K. Shaffner, Helv. aim. ... (b) SI Miller, Ph.D. Thesis, Temple ...

Research paper thumbnail of Bromohydrin formation in dimethyl sulfoxide

Journal of the American Chemical Society, 1968

The spectrometer was purchased from funds provided by a grant (CAO8841) from the National Cancer ... more The spectrometer was purchased from funds provided by a grant (CAO8841) from the National Cancer Institute, National Institutes of Health. We gratefully acknowledge this financial assistance. (20) H. 0. House, J. Amer. Chem. SOC., 77, 3070 (1955). (21) By comparison with mixtures of known composition, less than (22) A

Research paper thumbnail of Hindered rotation in substituted 1,2,3,4-tetrahydro-6,7-dimethoxyisoquinolines

Journal of the American Chemical Society, 1969

Conformational information concerning 1-and 2-substituted 1,2,3,4-tetrahydro-6,7-dimethoxyisoquin... more Conformational information concerning 1-and 2-substituted 1,2,3,4-tetrahydro-6,7-dimethoxyisoquinolines can be obtained by examination of the proton magnetic resonance (pmr) spectra of a suitable series of these compounds. The pmr spectra of 1,2,3,4-tetrahydro-2-acetyl-6,7-dimethoxyisoquinoline and its C-1 derivatives indicate the presence of unequal populations of two conformers at room temperature. The rates of exchange between the conformers were, in several cases, obtained from a match of experimental line widths (expanded sweeps) and calculated line widths as derived from the Gutowsky-Holm line shape equation. In the case of l-benzyl-2-acetyl-l,2,3,4-tetrahydro-6,7-dimethoxyisoquinoline the rates were obtained from the methoxy, acetyl, and aromatic resonances and each gave Arrhenius activation energies of 20.6 f 0.5 kcal/mole. The collective data for this series suggest that the two conformations observed reflect the two minimum energy conformations of N,N-disubstituted amides resulting from rotation of the N-acetyl group. This conclusion, as well as that concerning the value of the activation energy for the exchange process, differs markedly from that previously reached. Finally, in 2substituted 1-(o-aminobenzyl)-l,2,3,4-tetrahydro-6,7-dimethoxyisoquinolines, the location of the C-1 benzyl group appears to be a function of the size of the substituent in the 2 position.

Research paper thumbnail of Gas phase addition of hydrogen chloride to propylene

Journal of the American Chemical Society, 1975

Page 1. 5614 Chem. Soc., 94, 8934 (1972): (b) RJ Blint, TB McMahon. and JL Beauchamp, ibid., 96, ... more Page 1. 5614 Chem. Soc., 94, 8934 (1972): (b) RJ Blint, TB McMahon. and JL Beauchamp, ibid., 96, 1269 (1974). (2) JHJ Dawson. WG Henderson, RM D'Maliey, and KR Jennings, Int. J. Mass Spectrom. /on Phys., 11, 61 (1973). ...

Research paper thumbnail of Electron spin resonance studies on neutral aromatic hydrocarbon radicals

Journal of the American Chemical Society, 1969

Nmr Measurements. The pmr spectra were taken with a Varian HA-100 and an A-60A (or A-60) spectrom... more Nmr Measurements. The pmr spectra were taken with a Varian HA-100 and an A-60A (or A-60) spectrometers in about 10% solutions in D,O containing DSS as an internal reference at various temperatures. The lH,lH double-resonance experiments were carried out by using the HA-100 spectrometer operating at 100 MHz in the frequency-swept and DSS-locked mode with a Hewlett-Packard HP-200ABR audiooscillator. The peak positions were calibrated by direct readings of frequencies using a Hewlett-Packard HP-5212A electronic counter with accuracies to 50.1 Hz. The spectra taken with the A-60A (or A-60) spectrometer were calibrated by the usual side-band method. The lH,I*N double-resonance spectra of I and 111 at 100 MHz were recorded on the Varian HA-100 spectrometer equipped with an NMR Specialties HD-60B heteronuclear lH,l4N spin decoupler operating at about 7.224 MHz. All the spectra were taken in the frequency-swept and DSS-locked mode. The modulation frequencies were directly read by using the HP-5212A electronic counter. The lH,14N double-resonance spectrum of I at 60 MHz was measured with the Varian A-60 spectrometer equipped with an NMR Specialties HD-60A heteronuclear IH,I4N spin decoupler operating at about 4.33 MHz. The 14N nmr spectrum of I was determined with a Spectrospin AG (Zurich) HX-3 spectrometer at a frequency of 6.50 MHz (a field of about 21 kG) with simultaneous field-frequency locking on the N+(CH& proton resonance and 1H,14N decoupling of the CHB protons. The spectrometer was operated in the frequency-swept mode. The solution used was 3 0 x in DzO; the sample tube has 13 mm 0.d. Referencing was achieved by inserting a tube containing an acidified aqueous ammonium nitrate solution. Materials. Trimethylvinylammonium bromide (I) was commercially available. Trimethyl-(trans-pphenylviny1)ammonium bromide (11) was prepared according to Truce and SimmsS5l

Research paper thumbnail of Hindered Rotation in 1-Benzyl-1,2,3,4-tetrahydro-6-7-dimethoxyisoquinolines

Journal of the American Chemical Society, 1967

... Figures 3 and 4 depicit the aryl and acetyl resonances Fraenkel, Cava, Dalton 1 l-Benzyl-l,2,... more ... Figures 3 and 4 depicit the aryl and acetyl resonances Fraenkel, Cava, Dalton 1 l-Benzyl-l,2,3,4-tetrahydro-6,7-dimethoxyisoquinolines Page 4. ... Ber., 98, 2438 (1965); E. Vogel, W. A. Boll, and H. Gunther, Tetrahe-dron Letters, 609 (1965); JA Moore and J. Binkert, J. Am. ...

Research paper thumbnail of Decoration of the Aromatic Ring of Dihydrocodeinone (Hydrocodone) and 14-Hydroxydihydrocodeinone (Oxycodone)

The Journal of Organic Chemistry

Improved protocols for the preparation of 1-bromodihydrocodeinone (1-bromohydrocodone) and 1-brom... more Improved protocols for the preparation of 1-bromodihydrocodeinone (1-bromohydrocodone) and 1-bromo-14-hydroxydihydrocodeinone (1-bromooxycodone) and synthesis of the corresponding 1-chloro and 1-iodo derivatives have been achieved using the corresponding N-halosuccinimides in acidic milieu. The corresponding 1-carboethoxy derivative of 14-hydroxydihydrocodeinone (1-carboethoxyoxycodone) has been prepared by Pd-catalyzed reaction with carbon monoxide in ethanol. The ester was hydrolyzed to the corresponding zwitterionic amino acid.

Research paper thumbnail of The Dimethyl-p-dioxanes and the 2,5-Dibutyl-p-dioxanes

The Journal of Organic Chemistry, 1962

The isomeric dimethyl-p-dioxanes have been synthesized. Contrary to former reports, their boiling... more The isomeric dimethyl-p-dioxanes have been synthesized. Contrary to former reports, their boiling points are consistent with current theory. The boiling points of the 2,5-din -butyl-p-dioxanes are anomalous. helpful discussion and for loan of facilities while this manuscript was in preparation.

Research paper thumbnail of A New Isoquinuclidine Synthesis. A New Route to dl-Dioscorone 1

The Journal of Organic Chemistry, 1965

The Diels-Alder addition of l,&cyclohexadiene to methyleneurethan (generated in situ) yields 2-ca... more The Diels-Alder addition of l,&cyclohexadiene to methyleneurethan (generated in situ) yields 2-carbethoxy-2-azabicyclo [2.2.2]oct-5-ene (VII). The latter ester has been converted into isoquinuclidine (2-azabicyclo-[2,2.2]octanel I) and, in several steps, into dZ-dioscorone (IV).

Research paper thumbnail of MM2 force field parameters for oximes

The Journal of Organic Chemistry, 1988

The MM2 force field method has been extended to include oximes. Necessary parameters have been de... more The MM2 force field method has been extended to include oximes. Necessary parameters have been developed by using formaldoxime, (E)and (2)-acetaldoxime, a n d acetone oxime. The "methylene tilt" of formaldoxime has been successfully reproduced and calculated rotational barriers, moments of inertia, and dipole moments are in good agreement with the available experimental data.

Research paper thumbnail of Hofmann degradation of .beta.-hydroxy ammonium salts. II. 4-Hydroxybenzylisoquinolines and 4-hydroxyaporphines

The Journal of Organic Chemistry, 1987

Experimental Section IR spectra were recorded on a JASCO A-3 spectrophotometer. 'H NMR spectra we... more Experimental Section IR spectra were recorded on a JASCO A-3 spectrophotometer. 'H NMR spectra were recorded on a JEOL JNM-FX 90 Q (90 MHz) spectrometer in CDCl,, and chemical shifts are expressed in 6 values relation to Me4Si as internal standard. Coupling constants (4 are given in hertz. Mass spectra were obtained on a JEOL JMS-DX 300 instrument. GLPC analyses were performed on a JEOL JGC-2OK instrument with a 10% SE-30 column (1 m X 3 mm). Microanalyses were performed by the Microanalytical Laboratory in this institute. 2-Isopropylcyclohexanone (3).7 A mixture of 2-isopropylphenol (2) (3.0 g, 22 mmol) and Raney nickel (W-2,0.5 mL, 300 mg)I8 in ethanol (15 mL) was hydrogenated (initial pressure of H2 at 20 "C, 110 lb) in an externally heated stainless-steel autoclave at 100 "C for 4 h. The catalyst was removed by filtration through a pad of Celite, and the filtrate was diluted with ether and washed successively with 5% aqueous NaOH, water, and saturated brine. Evaporation of the solvent left an oil, an epimeric mixture of 2-isopropylcyclohexanols, which was submitted to the following oxidation without purification. To a cold solution of the crude cyclohexanols in acetic acid (23 mL) was added a 10% aqueous sodium hypochlorite solutions (19.8 mL, 26.5 mmol) in an ice bath and the mixture was further stirred for 1.5 h in the cold. The reaction mixture was poured into cold water and extracted with ether. The ether extract was successively washed with aqueous NaHC03, aqueous NaHSO,, water, and saturated brine. Removal of the solvent gave an oil, which was distilled under reduced pressure to give 3.01 g (97%) of 3: bp 82 "C (12 mmHg) [litS7" bp 90-98 "C (30 mmHg)]; IR (neat) 1708, 1370 cm-'; 'H NMR 0.89 (d, 6 H, J = 7), 1.2-2.4 (m, 10 H). l-Hydroxy-c-2-isopropyl-r-l-cyclohexanecarbonitrile and Its 2-Epimer (4a and 4b). To a solution of 3 (362 mg, 2.58 mmol) in ethanol (3.6 mL) was added at 0 "C acetone cyanohydrin (1.65 mL, 18.2 mmol) and K&O, (107 mg, 0.77 mmol), and the mixture was further stirred at 0-10 "C for 18 h. The mixture was diluted with ether and washed with water and saturated brine. Removal of the solvent gave 4 as an isomeric mixture, which in general was submitted to the following ring expansion without separation. For characterization, however, these compounds were separated by flash column chromatography [silica gel, hexane-ethyl acetate (8:l) as solvent] to give 60 mg (14%) of 4b and 340 mg (79%) of 4a as

Research paper thumbnail of Enantioselective Synthesis of Aza Sugars from Amino Acids. 2.1 The 3-Hydroxy-2-hydroxymethylpyrrolidines2

The Journal of Organic Chemistry, 2001

... Qing Lu, ‡ Jessica Vey, ‡ § David R. Dalton,* ‡ and Patrick J. Carroll ¶. ... The results her... more ... Qing Lu, ‡ Jessica Vey, ‡ § David R. Dalton,* ‡ and Patrick J. Carroll ¶. ... The results here are in concert with his observations. (12) See, for example: Goulet, MT In Encyclopedia of Reagents for Organic Synthesis; Paquette, L., Ed.; John Wiley & Sons: New York: 1995, Vol. ...

Research paper thumbnail of Surface-catalyzed hydrochlorination of alkenes. The reaction of the gases hydrogen chloride and 1,3-butadiene

The Journal of Organic Chemistry, 1991

NH3), m/e 329 (M + la), 311 (M). An isomer of C&,CH2CH2CH(C&&H2CH(C&&I-bH4CN mass (CI, NH3) 433 (... more NH3), m/e 329 (M + la), 311 (M). An isomer of C&,CH2CH2CH(C&&H2CH(C&&I-bH4CN mass (CI, NH3) 433 (M + 18) (20), 415 M (15). Other unidentified products. Electrolysis of 4-Chlorobenzonitrile in Liquid Ammonia in t h e Presence of Catalyst (4,4'-Bipyridine, 10-2 M) (Experiment 2). The procedure was the same as above. Beyond the products described in Table I, the following product was indentified in one of the chromatographic fractions from its mass spectrum. C&5CH2CH2CH(C&6)CHOHC6H4CN m/e 327 (561, 222 (24), 130 (loo), 105 (97), 102 (85). Acknowledgment. We are grateful to N. Morin (Ecole Normale Supgrieure) for her help in mass spectroscopy analysis.

Research paper thumbnail of Hydrochlorination of alkenes. 3. Reaction of the gases hydrogen chloride and (E)- and (Z)-2-butene

The Journal of Organic Chemistry, 1986

... (3) Maass, 0.; Coffin, C. C. Can. J . Res. 1930, 3, 526, 533 and refer-ences therein. (4) (a)... more ... (3) Maass, 0.; Coffin, C. C. Can. J . Res. 1930, 3, 526, 533 and refer-ences therein. (4) (a) Brearley, D.; Kistiakowsky, G. B.; Stauffer, H. J. J. Am. Chem. SOC. 1936,58,43. (b) Kistiakowsky, G. B.;Stauffer, HC Ibid 1937,59, 165. (5) Haugh, M. J.; Dalton, D. R. J. Am. Chem. ...

Research paper thumbnail of A molecular mechanics study of amide conformations

The Journal of Organic Chemistry, 1989

The MM2 force field has been extended to include amides using experimentally known geometries for... more The MM2 force field has been extended to include amides using experimentally known geometries for formamide, acetamide, and their N-methyl derivatives in the parameterization. Relative stabilities of conformers, barriers to rotation, and dipole moments are reproduced within reported experimental error. Additionally, a conformational study of acylpiperidines was performed. Although primary and secondary amides are found to be planar or nearly so, use of the N-methyl derivatives in the parameterization results in a significant deviation from planarity for tertiary amides.