An Unexpected Directing Effect in the Asymmetric Transfer Hydrogenation of α,α-Disubstituted Ketones
摘要:
alpha,alpha-Disubstituted ketones containing an aromatic ring or alkene are reduced in high enantiomeric excess using an asymmetric transfer hydrogenation catalyst. The sense of reduction indicates that the unsaturated region of the ketone adopts a position adjacent to the Ru-bound eta(6)-arene ring in the reduction transition state.
Metathetic approach to naphthoxepin and spirocyclic molecular frameworks
作者:Sambasivarao Kotha、Kalyaneswar Mandal
DOI:10.1016/j.tetlet.2003.12.075
日期:2004.2
An efficient method for the synthesis of naphthoxepin and spirocyclic skeletons starting from beta-naphthol has been developed. The Claisen rearrangement and the ring-closing metathesis reaction are used as key steps for their assembly. (C) 2004 Elsevier Ltd. All rights reserved.