Synthesis of New Allocolchicinoids with Seven- and Eight-Membered B-Rings by Enyne Ring-Closing Metathesis
作者:François-Didier Boyer、Issam Hanna
DOI:10.1002/ejoc.200800595
日期:2008.10
functionality in the C-ring at the C10 or C11 positions, is reported. An asymmetric synthesis of (7S)-allocolchicine 5 is also described. The main features included the elaboration of a common intermediate, the AB bicyclic ring system, in which the construction of the seven-membered ring was achieved by an enyne ring-closingmetathesis (RCM) reaction. A subsequent Diels–Alder/aromatization sequence afforded the
Gold(I)-Catalyzed Cycloisomerization of 1,7- and 1,8-Enynes: Application to the Synthesis of a New Allocolchicinoid
作者:François-Didier Boyer、Xavier Le Goff、Issam Hanna
DOI:10.1021/jo800797c
日期:2008.7.1
Gold(I)-catalyzedcycloisomerization of 1,7- and 1,8-enyne propargylic acetates afforded cyclopropyl derivatives containing seven- and eight-membered rings, respectively. This reaction was used for the synthesis of a new allocolchicinoid having a cyclopropane ring fused to the B seven-membered ring at the C6−C7 positions.