Dr.Farnoosh Farnia - Academia.edu (original) (raw)

Papers by Dr.Farnoosh Farnia

Research paper thumbnail of Photochemistry of ketones in solutions. 70. Identification of the reactive electronic excited state in the photocycloaddition of alkenes to cyclic enones

The Journal of Organic Chemistry, 1983

(H, s), 10.9 (H, s), 11.7 (H, 8). Anal. (CllHl4CIN02) C, H, N. 2f 86% from aldehyde;13 mp 156-157... more (H, s), 10.9 (H, s), 11.7 (H, 8). Anal. (CllHl4CIN02) C, H, N. 2f 86% from aldehyde;13 mp 156-157.5 'C; 'H NMR 6 1.25 (9 H, s), 7.486 (H, d, J = 2.3 Hz), 7.694 (H, d, J = 2.3 Hz), 8.37 (H, s), 10.8 (H, br s), 11.25 (H, br s). Anal. (Cl1Hl4IN02) C, H, N. Synthesis of 1,2-...

Research paper thumbnail of The photochemistry of carbohydrate derivatives. Part III. Photochemical rearrangements of 2,3- and 3,4-O-o-nitrobenzylideneglycopyranosides

Journal of the Chemical Society, Perkin Transactions 1, 1975

Research paper thumbnail of Ring opening of 2,3-, 3,4-, and 4,6-O-benzylidene acetals of pyranosides by photobromination with bromotrichloromethane

Journal of the Chemical Society, Chemical Communications, 1988

2, 3-3, 4-, and 4, 6-O-Benzylidene pyranoside derivatives on photobromination in bromotrichlorome... more 2, 3-3, 4-, and 4, 6-O-Benzylidene pyranoside derivatives on photobromination in bromotrichloromethane yield bromo-deoxy-pyranoside benzoates regio-and stereo-specifically which, for the acyl derivatives of the 2, 3-and 3, 4-acetals, is superior to their ...

Research paper thumbnail of Boron, Aluminum, and Gallium Tris(trifluoromethanesulfonate) (Triflate): Effective New Friedel–Crafts Catalysts

World Scientific Series in 20th Century Chemistry, 2003

Research paper thumbnail of Aluminum dichloride and dibromide. Preparation, spectroscopic (including matrix isolation) study, reactions, and role (together with alkyl(aryl)aluminum monohalides) in the preparation of organoaluminum compounds

Journal of the American Chemical Society, 1988

Anhydrous aluminum trichloride or bromide when heated in a 2:1 molar ratio with aluminum powder a... more Anhydrous aluminum trichloride or bromide when heated in a 2:1 molar ratio with aluminum powder as a suspension in dry n-heptane or methylcyclohexane was found to be partially reduced to aluminum dichloride or dibromide. Ultrasound treatment (sonication) significantly promotes the reaction. Aluminum dichloride in higher purity was obtained by the reaction of gaseous aluminum trichloride with aluminum metal in a high-vacuum reactor, allowing subsequent investigation by IR spectroscopy. An aluminum sub-halide of the form A12(i-Bu)6xClx was also prepared through the reaction of tetraisobutyldialane and HCl at low temperature. Both materials were investigated by IR spectroscopy and compared to A1C12 prepared and isolated through the codeposition of aluminum atoms and molecular chlorine in a solid argon matrix. The matrix study characterized A1C12 together with AlCl and AICI,, which were also formed in the system. The paramagnetic aluminum dihalides, i.e. AIClz and AlBr,, are associated in the condensed state (except under matrix isolation conditions where they are monomeric). An ESR study of the pyridinium complex of AIClz was carried out and showed its paramagnetic nature. In the present study, for simplicity, the reactions of aluminum dihalides are considered as those of the dimers but could involve higher associated oligomers. MNDO calculations on the heats of formation of several possible isomeric structures of Al2CI4 indicate the preference for both halogen bridging and significant AI-A1 bonding in the dimer. Reaction of AlC1, + A1 with ethylene, the Hall and Nash reaction, was reinvestigated by I3C and 27Al NMR spectroscopy. The reaction was found to give, besides ethylaluminum sesquichloride, 1,2-and 1 ,I-bis(dichloroa1uminio)ethanes. Cyclohexene in a similar reaction gives, although less readily, 1,2-bis(dichloroaluminio)cyclohexane. The reactions are indicative of addition of (A1C12)2 to the olefins. Alkyl-and arylaluminum monohalides are intermediately formed in the reaction of alkyl halides or halobenzenes with active aluminum powder. These divalent aluminum halides are also considered to be dimeric in nature and immediately react with excess of the alkyl (aryl) halides to form the corresponding sesquihalides. Io contrast, aluminum dihalides formed in the aluminum trihalide-aluminum metal systems react with alkyl or aryl halides to give alkyl(ary1)aluminum dihalides. Sonication was found to significantly promote these reactions.

Research paper thumbnail of Superacid-catalyzed near-quantitative isomerization of C4n+6H4n+12 (n = 1-3) polycyclic precursors to diamondoid cage hydrocarbons promoted by 1-haloadamantanes and sonication

The Journal of Organic Chemistry, 1988

(Cs), 171.76 (CJ, 96.75 (Ch), 76.51 (C3), 37.41 (C4), 32.9 (Ck), 29.48 ... (m, JH -H3 = 8.4, JH4B... more (Cs), 171.76 (CJ, 96.75 (Ch), 76.51 (C3), 37.41 (C4), 32.9 (Ck), 29.48 ... (m, JH -H3 = 8.4, JH4B-H3 = 6.5, Jgem = 16.4,2 H4), 4.72 (m, JH3-H4* = 8.4, Q(H3-Hm = 6.5, JH3<H3 = 6.3, H3), 6.71 (dd, JHr% = 8.4, JH,H5 = 1.0, H7), 6.86 (dd, JHsHs = 7.4, JHsH = 1.0, H&, 7.42 ...

Research paper thumbnail of Synthesis of methyl 3-O-(α- and β-d-galactopyranosyl)4-O-(β-d-glucopyranosyluronic acid)-α-l-rhamnopyranoside using photolabile methyl 2,3-O-(2-nitrobenzylidene)-α-l-rhamnopyranoside

Carbohydrate Research, 1985

The title branched-trisaccharide derivatives (9 and 13) have been synthesised from methyl 2,3-O-(... more The title branched-trisaccharide derivatives (9 and 13) have been synthesised from methyl 2,3-O-(2-nitrobenzylidene)-a-L-rhamnopyranoside (2) using the 2nitrobenzylidene residue as a temporary blocking-group. Condensation of 2 with methyl (2,3,4-triO -acetyl-aD -glucopyranosyl bromide)uronate afforded the blocked disaccharide 3 which, on sequential photolysis and oxidation, gave methyl 4-0-(methyl 2,3,4-triO -acetyl-~-D-glucopyranosyluronate)-2-O-(Znitrobenzoyl)-(4) and-3-0-(2-nitrobenzoyl)-cY-L-rhamnopyranoside (5) as a 4: 1 mixture. Galactosylation of HO-3 of 4 gave two fully protected trisaccharides having paa and /3@ configuration which, on deacylation, saponification, and treatment with ionexchange resins, gave the free acids 9 and 13.

Research paper thumbnail of A 4-oxacyclohexanone-1,5-lactone photoisomerization with 1,2:4,6-Di-O-alkylidene-α-D-hexopyranos-3-ulose derivatives

J. Chem. Soc., Chem. Commun., 1985

Five 4-oxacyclohexanones (1)-(5) derived from 1,2 : 4,6-di-O-alkylidene glucose have been shown t... more Five 4-oxacyclohexanones (1)-(5) derived from 1,2 : 4,6-di-O-alkylidene glucose have been shown to photoisomerize to the 2,3 : 4,6-di-U-al kylidene-aldono-I ,5-lactones (7)-(11) respectively. The photoreactions of 3-oxacyclohexanone derivatives prepared from carbohydrates have been found1 to be influenced by the nature and position of the numerous alkoxy substituents present on the ring. The photoisomerization of sugar derivatives possessing the less studied 4-oxacyclohexanone structure we describe here, compared with earlier reported2 reactions on closely related compounds, indicates that their photochemistry is also dependent on the protecting groups. U .v.-irradiation of the 4-oxacyclohexanone, 4,6-0-ethylidene-1,2-O-isopropylidene-a-~-ri6o-hexopyranos-3-ulose (1) in acetonitrile? solution gave one non-polar product which t Irradiations were carried out on 1-5% solutions in quartz tubes with a 450 W Hanovia medium pressure Hg lamp. New compounds were characterized by elemental analysis and/or mass spectroscopy and by '€4 and 13C n.m.r. spectroscopy.

Research paper thumbnail of Photochemistry of ketones in solutions. 70. Identification of the reactive electronic excited state in the photocycloaddition of alkenes to cyclic enones

The Journal of Organic Chemistry, 1983

(H, s), 10.9 (H, s), 11.7 (H, 8). Anal. (CllHl4CIN02) C, H, N. 2f 86% from aldehyde;13 mp 156-157... more (H, s), 10.9 (H, s), 11.7 (H, 8). Anal. (CllHl4CIN02) C, H, N. 2f 86% from aldehyde;13 mp 156-157.5 &amp;#x27;C; &amp;#x27;H NMR 6 1.25 (9 H, s), 7.486 (H, d, J = 2.3 Hz), 7.694 (H, d, J = 2.3 Hz), 8.37 (H, s), 10.8 (H, br s), 11.25 (H, br s). Anal. (Cl1Hl4IN02) C, H, N. Synthesis of 1,2-...

Research paper thumbnail of The photochemistry of carbohydrate derivatives. Part III. Photochemical rearrangements of 2,3- and 3,4-O-o-nitrobenzylideneglycopyranosides

Journal of the Chemical Society, Perkin Transactions 1, 1975

Research paper thumbnail of Ring opening of 2,3-, 3,4-, and 4,6-O-benzylidene acetals of pyranosides by photobromination with bromotrichloromethane

Journal of the Chemical Society, Chemical Communications, 1988

2, 3-3, 4-, and 4, 6-O-Benzylidene pyranoside derivatives on photobromination in bromotrichlorome... more 2, 3-3, 4-, and 4, 6-O-Benzylidene pyranoside derivatives on photobromination in bromotrichloromethane yield bromo-deoxy-pyranoside benzoates regio-and stereo-specifically which, for the acyl derivatives of the 2, 3-and 3, 4-acetals, is superior to their ...

Research paper thumbnail of Boron, Aluminum, and Gallium Tris(trifluoromethanesulfonate) (Triflate): Effective New Friedel–Crafts Catalysts

World Scientific Series in 20th Century Chemistry, 2003

Research paper thumbnail of Aluminum dichloride and dibromide. Preparation, spectroscopic (including matrix isolation) study, reactions, and role (together with alkyl(aryl)aluminum monohalides) in the preparation of organoaluminum compounds

Journal of the American Chemical Society, 1988

Anhydrous aluminum trichloride or bromide when heated in a 2:1 molar ratio with aluminum powder a... more Anhydrous aluminum trichloride or bromide when heated in a 2:1 molar ratio with aluminum powder as a suspension in dry n-heptane or methylcyclohexane was found to be partially reduced to aluminum dichloride or dibromide. Ultrasound treatment (sonication) significantly promotes the reaction. Aluminum dichloride in higher purity was obtained by the reaction of gaseous aluminum trichloride with aluminum metal in a high-vacuum reactor, allowing subsequent investigation by IR spectroscopy. An aluminum sub-halide of the form A12(i-Bu)6xClx was also prepared through the reaction of tetraisobutyldialane and HCl at low temperature. Both materials were investigated by IR spectroscopy and compared to A1C12 prepared and isolated through the codeposition of aluminum atoms and molecular chlorine in a solid argon matrix. The matrix study characterized A1C12 together with AlCl and AICI,, which were also formed in the system. The paramagnetic aluminum dihalides, i.e. AIClz and AlBr,, are associated in the condensed state (except under matrix isolation conditions where they are monomeric). An ESR study of the pyridinium complex of AIClz was carried out and showed its paramagnetic nature. In the present study, for simplicity, the reactions of aluminum dihalides are considered as those of the dimers but could involve higher associated oligomers. MNDO calculations on the heats of formation of several possible isomeric structures of Al2CI4 indicate the preference for both halogen bridging and significant AI-A1 bonding in the dimer. Reaction of AlC1, + A1 with ethylene, the Hall and Nash reaction, was reinvestigated by I3C and 27Al NMR spectroscopy. The reaction was found to give, besides ethylaluminum sesquichloride, 1,2-and 1 ,I-bis(dichloroa1uminio)ethanes. Cyclohexene in a similar reaction gives, although less readily, 1,2-bis(dichloroaluminio)cyclohexane. The reactions are indicative of addition of (A1C12)2 to the olefins. Alkyl-and arylaluminum monohalides are intermediately formed in the reaction of alkyl halides or halobenzenes with active aluminum powder. These divalent aluminum halides are also considered to be dimeric in nature and immediately react with excess of the alkyl (aryl) halides to form the corresponding sesquihalides. Io contrast, aluminum dihalides formed in the aluminum trihalide-aluminum metal systems react with alkyl or aryl halides to give alkyl(ary1)aluminum dihalides. Sonication was found to significantly promote these reactions.

Research paper thumbnail of Superacid-catalyzed near-quantitative isomerization of C4n+6H4n+12 (n = 1-3) polycyclic precursors to diamondoid cage hydrocarbons promoted by 1-haloadamantanes and sonication

The Journal of Organic Chemistry, 1988

(Cs), 171.76 (CJ, 96.75 (Ch), 76.51 (C3), 37.41 (C4), 32.9 (Ck), 29.48 ... (m, JH -H3 = 8.4, JH4B... more (Cs), 171.76 (CJ, 96.75 (Ch), 76.51 (C3), 37.41 (C4), 32.9 (Ck), 29.48 ... (m, JH -H3 = 8.4, JH4B-H3 = 6.5, Jgem = 16.4,2 H4), 4.72 (m, JH3-H4* = 8.4, Q(H3-Hm = 6.5, JH3<H3 = 6.3, H3), 6.71 (dd, JHr% = 8.4, JH,H5 = 1.0, H7), 6.86 (dd, JHsHs = 7.4, JHsH = 1.0, H&, 7.42 ...

Research paper thumbnail of Synthesis of methyl 3-O-(α- and β-d-galactopyranosyl)4-O-(β-d-glucopyranosyluronic acid)-α-l-rhamnopyranoside using photolabile methyl 2,3-O-(2-nitrobenzylidene)-α-l-rhamnopyranoside

Carbohydrate Research, 1985

The title branched-trisaccharide derivatives (9 and 13) have been synthesised from methyl 2,3-O-(... more The title branched-trisaccharide derivatives (9 and 13) have been synthesised from methyl 2,3-O-(2-nitrobenzylidene)-a-L-rhamnopyranoside (2) using the 2nitrobenzylidene residue as a temporary blocking-group. Condensation of 2 with methyl (2,3,4-triO -acetyl-aD -glucopyranosyl bromide)uronate afforded the blocked disaccharide 3 which, on sequential photolysis and oxidation, gave methyl 4-0-(methyl 2,3,4-triO -acetyl-~-D-glucopyranosyluronate)-2-O-(Znitrobenzoyl)-(4) and-3-0-(2-nitrobenzoyl)-cY-L-rhamnopyranoside (5) as a 4: 1 mixture. Galactosylation of HO-3 of 4 gave two fully protected trisaccharides having paa and /3@ configuration which, on deacylation, saponification, and treatment with ionexchange resins, gave the free acids 9 and 13.

Research paper thumbnail of A 4-oxacyclohexanone-1,5-lactone photoisomerization with 1,2:4,6-Di-O-alkylidene-α-D-hexopyranos-3-ulose derivatives

J. Chem. Soc., Chem. Commun., 1985

Five 4-oxacyclohexanones (1)-(5) derived from 1,2 : 4,6-di-O-alkylidene glucose have been shown t... more Five 4-oxacyclohexanones (1)-(5) derived from 1,2 : 4,6-di-O-alkylidene glucose have been shown to photoisomerize to the 2,3 : 4,6-di-U-al kylidene-aldono-I ,5-lactones (7)-(11) respectively. The photoreactions of 3-oxacyclohexanone derivatives prepared from carbohydrates have been found1 to be influenced by the nature and position of the numerous alkoxy substituents present on the ring. The photoisomerization of sugar derivatives possessing the less studied 4-oxacyclohexanone structure we describe here, compared with earlier reported2 reactions on closely related compounds, indicates that their photochemistry is also dependent on the protecting groups. U .v.-irradiation of the 4-oxacyclohexanone, 4,6-0-ethylidene-1,2-O-isopropylidene-a-~-ri6o-hexopyranos-3-ulose (1) in acetonitrile? solution gave one non-polar product which t Irradiations were carried out on 1-5% solutions in quartz tubes with a 450 W Hanovia medium pressure Hg lamp. New compounds were characterized by elemental analysis and/or mass spectroscopy and by '€4 and 13C n.m.r. spectroscopy.