In contrast to its 20-epimer, the formolysis of 3β-acetoxy-5α-pregnan-20α-yl tosylate proceeds predominantly without enlargement of the D ring. The products were identified as 17β-methyl-18-nor-5α, 17α-pregn-13-en-3β-yl acetate (2b), 3β-acetoxy-5α-pregnan-20α-yl formate (13), 3β-acetoxy-17-α-methyl-D-homo-5α-androstan-17αβ-yl formate (14). 5α-pregn-20-en-3β-yl acetate (12b) and 3β-acetoxy-5α-pregnan-20β-yl
Stereoelectronic and steric effect in the Baeyer–Villiger rearrangement of steroidal α-chlorocyclobutanones
作者:Zdzisław Paryzek、Hanna Koenig
DOI:10.1016/j.tet.2012.08.060
日期:2012.11
exclusive formation of γ-chloro-γ-lactone results from the migration of the chlorinated substituent (CHCl) versus the alkyl group (CH2), contrary to the expected migratory aptitude. In explaining the unusual regioselectivity observed in these reactions, steric effects and dipole interactions in the formation of the reactive Criegee intermediates are considered and the stereoelectronic effect is postulated
Fragrance Compositions and Other Compositions Which Contain Naturally Occurring Substances Found in Corals
申请人:Human Pheromone Sciences, Inc.
公开号:US20140045805A1
公开(公告)日:2014-02-13
This invention is generally related to the fields of fragrance compositions, personal care products, and home consumer products. This invention also relates to 20-pregnenes, in particular those found naturally occurring in corals and which affect mood in humans, to the incorporation of these 20-pregnene compounds into various compositions, and to methods of affecting the mood of individuals using such compounds.
Synthesis of the isomeric 3β-acetoxy-20-chloro-5α-pregnanes
作者:R Li
DOI:10.1016/0039-128x(69)90055-5
日期:1969.4
Reaction of (20S)-3.BETA.-acetoxybisnorchol-5-enic acid with lead tetraacetate. Structure of pregnane derivatives and a dimer.
作者:YOSHIHIRO SATO、YOSHIKO SONODA
DOI:10.1248/cpb.30.822
日期:——
Reaction of 3β-acetoxybisnorchol-5-enic acid (1) with lead tetraacetate in benzene gave ⊿20 and ⊿17 (20) compounds (2a and 2b) and 20α-and 20β-acetoxy compounds (3a and 3b), with a trace of 20-keto compound (4) and a dimer (5). The structure of 5 was determined as 3'β-acetoxypregn-5'-en-20'α-yl 3β-acetoxybisnorchol-5-enate (Chart 1). The use of toluene or xylene in place of benzene resulted in decreased formation of 2b with the formation of the 17-ethyl compound (2c). The reactions were examined under various conditions (Table I) and the reaction mechanisms are discussed.