Ein Syntheseäquivalent für [2.2]Paracyclophan-1,9-diin: Octaphenyl-1:2,9:10-dibenzo[2.2]paracyclophan-1,9-dien und seine Reduktion zum Hexaanion (original) (raw)
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Neue [2.2]Paracyclophan-1,9-diene aus 1,9(10)-Dibrom-[2.2]paracyclophan-1,9-dien
Chemische Berichte, 1987
Das durch Photobromierung von [2.2]Paracyclophan (1) crhiiltliche Gemisch aus 1,1,9,9-und 1,1,10,10-Tetrabrom[2.2]pcyclophan (4) lieferte mit Kaliurn-tert-butylat in tert-Butylmethylether die 1,9(lO)-Dibrom[2.2]paracyclophan-l,9-diene (5). Hieraus lie Ben sich in jeweils einem Schritt (22]Paracyclophan-1,9-dien (2) und 1 S(lO)-Bi~trimethylsilyl~2.2]paracyclopha-l,9-dien (12) gewinoea. Palladium(0)-katalysierte Kupplungem von 5 rnit Vinyl-Z-Substratcn (2 = H, SiMe,, CHO, COzMe und Phenyl} ergaben neue briickensubstituierte Divinyl-Derivate 14 des [2.2]Paracyclophan-l94ens, die durch Diels-Alder-Addition geeigneter Di-
Archiv der Pharmazie, 1988
Pethidin-Analoga mit eingeschrankter Konformation, 1. Mitt. Synthese von cis-und trans-4-Methyl-lob-carbethoxymethyl
Zeitschrift für Naturforschung B, 1995
The title compound (S,S)-2, has been obtained by reduction with Li[AlH4] of the cyclopentane- 1,2-diyl-bis(1′,3′,2′-dioxaphospholane) (1S ,2S)-trans-C5H8[P(OCH (CO2Pr-i)- (R) - )2]2, (S,S)-1, which itself was isolated in diastereomerically pure form (X-ray structure analysis) from the reaction between rac, trans-C5H8(PCl2)2 and (2R,3R)-(+)-diisopropyl tartrate. Cleavage of (S,.S)-1 withPCl3 yielded an unseparable mixture of (1S,2S)-trans-C5H8(PCl2)2 and (4R.5R) -ClP [OCH(CO2Pr-i)-]2.
Chemische Berichte, 1982
The reaction of the ketone 1, m =0, with diazocyclopropane proceeds predominantly to the spiroalkylation product 9, m = 0, with a minor amount of the homologation product 1, m = 1. The use of the sulfonimide 23 significantly increases the yield of 1, m = 1, however the production of 9, m = 0, remains dominant. The product distributions are discussed in terms of possible reaction mechanisms. Die Synthese funktionalisierter Polyspirane und [n]Rotane wurde erheblich vereinfacht, wenn die schrittweise Homologisierung 1-+ 2 + 3-+ 4-+ 1 ') durch eine Mehrfach-3 4
Helv Chim Acta, 1990
Glycolaldehyde phosphate aldomerizes in aqueous NaOH solution to a product mixture containing the racemates of the two diastereoisomeric tetrose 2,4-diphosphates and eight hexose 2,4,6-triphosphates. At room temperature in the absence of air and after 7 days, a solution 0 . 0 8~ in glycolaldehyde phosphate (= formylmethyl dihydrogenphosphate) and 2M in NaOH gives products, in up to 80% yield, with a tetrose/hexose derivative ratio of ca. 1 : 10 and with rue-allose 2,4,6-triphosphate comprising up to 50% of the mixture of sugar phosphates. When the reaction is run under the same conditions but in the presence of 0.5 mol-equiv. of formaldehyde, sugar phosphates are formed in up to 45% yield, with pentose 2,4-diphosphates now predominating over hexose triphosphates by a ratio of 3:1. rue-Ribose 2,4-diphosphate is found to be the major component, the ratios among ribose, arabinose, lyxose, and xylose 2,4-diphosphates being 52:14: 23: 11 in a representative experiment. The pentose diphosphates are constitutionally stable under the reaction conditions (observed for 23 weeks), but the diastereoisomeric ratios slowly change with time (to 22:34:30:14 after 23 weeks), showing that ribose 2,4-diphosphate is not the thermodynamically favored diastereoisomer. The observed product distributions in both the pentose and the hexose series (after 1 week) reveal an aldolization mode that is preferentially erythro in the product-determining step (the reaction of glycolaldehyde phosphate as its enolate with glycerinaldehyde 2-phosphate and tetrose 2,4-diphosphdte, respectively). An attempt is made to rationalize both this fact and the kinetic predominance of ribose 2,4-diphosphate in the pentose series and allose 2,4,6-triphosphate in the hexose series. Their configuration along the C-chain can be interpreted as corresponding to a minimum number of 1-5 repulsions in the packing of phosphate and OH substituents and minimal steric interaction between substituents at the reaction centers in the transition state of the product-determining step. The aldomerization of glycolaldehyde phosphate in the presence of formaldehyde is a variant of the formose reaction. It avoids the formation of complex formose product mixtures, largely as a consequence of the fact that aldoses which are phosphorylated at the C(2) 4. Mitteilung uber die Chemie von a -Aminonitrilen. 3. Mitteilung: [I].
Helvetica Chimica Acta, 1990
Glycolaldehyde phosphate aldomerizes in aqueous NaOH solution to a product mixture containing the racemates of the two diastereoisomeric tetrose 2,4-diphosphates and eight hexose 2,4,6-triphosphates. At room temperature in the absence of air and after 7 days, a solution 0 . 0 8~ in glycolaldehyde phosphate (= formylmethyl dihydrogenphosphate) and 2M in NaOH gives products, in up to 80% yield, with a tetrose/hexose derivative ratio of ca. 1 : 10 and with rue-allose 2,4,6-triphosphate comprising up to 50% of the mixture of sugar phosphates. When the reaction is run under the same conditions but in the presence of 0.5 mol-equiv. of formaldehyde, sugar phosphates are formed in up to 45% yield, with pentose 2,4-diphosphates now predominating over hexose triphosphates by a ratio of 3:1. rue-Ribose 2,4-diphosphate is found to be the major component, the ratios among ribose, arabinose, lyxose, and xylose 2,4-diphosphates being 52:14: 23: 11 in a representative experiment. The pentose diphosphates are constitutionally stable under the reaction conditions (observed for 23 weeks), but the diastereoisomeric ratios slowly change with time (to 22:34:30:14 after 23 weeks), showing that ribose 2,4-diphosphate is not the thermodynamically favored diastereoisomer. The observed product distributions in both the pentose and the hexose series (after 1 week) reveal an aldolization mode that is preferentially erythro in the product-determining step (the reaction of glycolaldehyde phosphate as its enolate with glycerinaldehyde 2-phosphate and tetrose 2,4-diphosphdte, respectively). An attempt is made to rationalize both this fact and the kinetic predominance of ribose 2,4-diphosphate in the pentose series and allose 2,4,6-triphosphate in the hexose series. Their configuration along the C-chain can be interpreted as corresponding to a minimum number of 1-5 repulsions in the packing of phosphate and OH substituents and minimal steric interaction between substituents at the reaction centers in the transition state of the product-determining step. The aldomerization of glycolaldehyde phosphate in the presence of formaldehyde is a variant of the formose reaction. It avoids the formation of complex formose product mixtures, largely as a consequence of the fact that aldoses which are phosphorylated at the C(2) 4. Mitteilung uber die Chemie von a -Aminonitrilen. 3. Mitteilung: [I].
Liebigs Annalen der Chemie, 1981
Eingegangen am 21. April 1980 Das Sila-Dimetacrin (3a), ein Sila-Analogon des Psychopharmakons Dimetacrin (2), und sein N,N-Diethylderivat 3 b sowie sein 3-Chlorderivat 3 c wurden, von den o-Halogenanilinen 4 a-c ausgehend, uber die teilweise unbekannten Stufen 5 a-c bis 10a-d synthetisiert, in ihren Eigenschaften beschrieben und in ihrer Struktur uber Elernentaranalysen, 'H-NMR-und Massenspektren sichergestellt. Die Synthese des Zwischenproduktes Bis(2-brompheny1)amin (9 a) konnte optimiert werden. Sila-Pharmaca, 23 I).-9,9-Dimethyl-l0-(3-dimethylaminopropyl)-9-silaacridane, a Sila-Analogue of Dimetacrine, and Structurally Related Compounds Sila-dimetacrine (3a), a sila-analogue of the psychotropic drug dirnetacrine (Z), and its N,N-diethyl derivative 3 b as well as its 3-chloro derivative 3c were synthesized from o-haloanilines 4 a-c via thepartially unknownintermediates 5 a-c to 10a-d. Their properties are described and their structure is confirmed by elemental analysis, 'H-NMR, and mass spectroscopy. The preparation of the intermediate bis(2-bromopheny1)amine (9a) could be improved.