Acid-Promoted Rearrangement of Cyclic α,β-Epoxy Acylates: Stereoselective Synthesis of Spirocyclanes and Quaternary Carbon Centers
摘要:
The rearrangement reaction of alpha,beta-epoxy acylates in cyclic systems was studied. The treatment of cis-derivatives with a Lewis acid afforded rearranged products via the regioselective B-cleavage of the oxirane ring due to the electron-withdrawing nature of the acyloxy group, whereas trans-derivatives enhanced the neighboring group participation to yield only a small amount of rearranged products. This rearrangement reaction proved to be useful for the construction of st variety of spirocyclane systems or quaternary carbon centers on rings and could be applied to their syntheses as optically active forms.
[EN] 1-HYDROXY-OCTAHYDROAZULENES AS FRAGRANCES<br/>[FR] 1-HYDROXY-OCTAHYDROAZULÈNES EN TANT QUE PARFUMS
申请人:GIVAUDAN SA
公开号:WO2012001018A1
公开(公告)日:2012-01-05
(3S,5R)-3,8-dimethyl-5-(prop-1-en-2-yl)-octahydroazulen-1-ols, their use as flavour or fragrance ingredient, and a process of their production by oxidation in the presence of laccase.
Asymmetric synthesis of chiral spirocyclanes: Selective formation of 2-acyloxy-1-oxospiro[4.n]alkanes by regio- and stereoselective rearrangement of α,β-epoxy acylates in bicyclo[n.3.0]alkane systems
作者:Hiromichi Fujioka、Shinji Kitagaki、Reiko Imai、Michinori Kondo、Sachi Okamoto、Yutaka Yoshida、Shuji Akai、Yasuyuki Kita
DOI:10.1016/0040-4039(95)00517-g
日期:1995.5
Selective formation of 2-acyloxy-1-oxospiro[4.n]alkanes by regio- and stereoselective rearrangement of α,β-epoxy acylates in bicyclo[n.3.0]alkane systems has been achieved; the effect of the acyloxy group and stereochemistry of the starting epoxides were studied. The reaction was successfully applied to the synthesis of an optically active chiral spiro compound.