Synthesis of 1,3-Dioxin-4-ones and Their Use in Synthesis. 21. Intramolecular Photo[2+2]cycloaddition Reactions of Chiral Spirocyclic Dioxinones Having w-Alkenyl Groups at 3-Position
Development of a Method for the Reductive Cyclization of Enones by a Titanium Catalyst
作者:Natasha M. Kablaoui、Stephen L. Buchwald
DOI:10.1021/ja954192n
日期:1996.1.1
which bis(trimethylphosphine)titanocene is used to catalyze the reductive cyclization of enones to cyclopentanols via a metallacyclic intermediate has been developed. The key step in the process is the cleavage of the titanium−oxygen bond in the metallacycle by a silane to regenerate the catalyst. Mechanistic aspects of the reaction are discussed and the diastereoselectivity of the transformation is studied
Intramolecular cross-ring enone–alkene photoannelation in 6-(ω-alkenyl)-cyclohex-2-en-1-ones
作者:A. B. Lakshmi、Jampani Madhusudana Rao
DOI:10.1039/c39910000476
日期:——
The irradiation of some 6-(Ï-alkenyl)-cyclohex-2-en-1-ones in micelles gave a carbonyl bridged intramolecular photoadduct but the reaction is restricted to enones tethered to an alkene by not more than a four-carbon chain.