Electrolytic decarboxylation reactions. 4. Electrosyntheses of 3-alkyl-2-cycloalken-1-ol acetates from 1-alkyl-2-cycloalkene-1-carboxylic acids. Preparation of dl-muscone from cyclopentadecanone
The Profound Effect of the Ring Size in the Electrocyclic Opening of Cyclobutene-Fused Bicyclic Systems
作者:Michael J. Ralph、David C. Harrowven、Steven Gaulier、Sean Ng、Kevin I. Booker-Milburn
DOI:10.1002/anie.201410115
日期:2015.1.26
Fused cyclobutenes, prepared by the photocycloaddition of propargyl alcohols to cyclic anhydride chromophores, undergo facile thermochemical ringopening to fused γ‐lactones. The size of the fused ring profoundly influences the temperature that is required to facilitate the ringopening (from 50 °C to 180 °C) and the nature of the product that is formed. Our studies provide new insights into the mechanistic
Free radical-promoted, one-carbon, ring expansion of twelve, fourteen-, and fifteen-membered cyclic β-keto esters is described. The method is then extended to include a three-carbon ring expansion of cyclododecanone, the targets being (±)-muscone and naturally occurring (R)-(−)muscone.
DieCope-Umlagerung als Prinzip einer repetierbaren Ringerweiterung
作者:Jens Bruhn、Heinz Heimgartner、Hans Schmid
DOI:10.1002/hlca.19790620814
日期:1979.12.12
The Cope Rearrangement, a Reaction for Repeatable Ring Expansions
应付重排,可重复的环扩展反应
Free radical ring expansion and rearrangement of large carbocyclic rings
作者:Paul Dowd、Soo-Chang Choi
DOI:10.1016/s0040-4039(00)74828-3
日期:1991.1
Free radical initiated ringexpansion of twelve-, thirtheen-, and fourteen-membered carbocyclicrings is described together with a new synthesis of (R)-(−)-muscone.
An efficient, practical, and stereocontrolled synthesis of (Z)-civetone (1), a representative musk perfume, has been performed utilizing a Ti-Dieckmann (intramolecular Ti-Claisen) condensation of dimethyl (Z)-9-octadecenedioate (3) as the key step. This cyclization reaction has some advantages compared with the traditional basic Dieckmann condensation such as higher concentration (100–300 mM), lower