Applications of highly enantioenriched alcohols bearing a phenylthio group in the preparation of ring compounds. The two-pot synthesis of an enantiopure spiroacetal pheromone bearing three chiral centers
摘要:
The new chiron (S)-6-phenylthio-2-hexanol (3) was prepared in high enantiomeric excess by baker's yeast reduction of the corresponding ketone. Enantioenriched alcohols 1, 2 and 3, prepared previously by a similar procedure, or their racemic counterparts, were transformed into ring closed compounds 5-methyl-2-(phenylthio)tetrahydrofuran (9), 6-methyl-2-(phenylthio)tetrahydropyran (10), 2-methyl-1-phenylsulfonyl cyclopropane (14), cyclobutane (15), cyclopentane (16), and a bee pheromone, (2S,6R,8S)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane (20). (C) 1997 Elsevier Science Ltd.
Divergent Synthesis of β-Fluoroamides via Silver-Catalyzed Oxidative Deconstruction of Cyclopropanone Hemiaminals
作者:Yujin Jang、Weixia Deng、Ivan S. Sprague、Vincent N. G. Lindsay
DOI:10.1021/acs.orglett.3c01992
日期:2023.7.21
approach for the synthesis of challenging β-fluoroamides from readily accessible cyclopropanone equivalents is reported. Following the addition of pyrazoleused here as a transient leaving group, silver-catalyzed regiospecific ring-opening fluorination of the resulting hemiaminal leads to a β-fluorinated N-acylpyrazole intermediate reactive to substitution with amines, ultimately affording β-fluoroamides
Vitamin B<sub>12</sub>‐Photocatalyzed Cyclopropanation of Electron‐Deficient Alkenes Using Dichloromethane as the Methylene Source**
作者:John Hayford G. Teye‐Kau、Mayokun J. Ayodele、Spencer P. Pitre
DOI:10.1002/anie.202316064
日期:2024.1.8
We report a vitamin B12-photocatalyzed strategy for the cyclopropanation of electron-deficient alkenesusing dichloromethane (CH2Cl2) as the methylene source. The reaction has excellent functional group tolerance, is highly chemoselective, and the scope can be extended to other 1,1-dichloroalkanes for the preparation of D2-cyclopropyl and methyl-substituted cyclopropyl adducts, all of which are important
Synthesis of substituted tetrahydrofurans via intermolecular reactions of γ-chlorocarbanions of 3-substituted 3-chloro-propylphenyl sulfones with aldehydes
Carbanions of 3-substituted-3-chloropropyl phenyl sulfones add to carbonyl groups of aldehydes to produce aldol type adducts that undergo 1,5-intramolecular substitution giving 2,3,5-trisubstituted tetrahydrofurans. The effect of substituents in the 3-position of these sulfones on the relative rates of 1,3-intramolecular substitution of the corresponding gamma-chlorocarbanions and their intramolecular addition are disclosed. (C) 2010 Elsevier Ltd. All rights reserved.
Tanaka, Kazuhiko; Suzuki, Hitomi, Journal of the Chemical Society. Perkin transactions I, 1992, # 16, p. 2071 - 2074
作者:Tanaka, Kazuhiko、Suzuki, Hitomi
DOI:——
日期:——
Tanikaga, Rikuhei; Shibata, Noriaki; Yoneda, Takamitsu, Journal of the Chemical Society. Perkin transactions I, 1997, # 15, p. 2253 - 2257