A One-Pot, Base-Free Annelation Approach to α-Alkylidene-γ-butyrolactones
作者:Russell R. A. Kitson、Richard J. K. Taylor、John L. Wood
DOI:10.1021/ol902191d
日期:2009.11.19
A novel annelation procedure has been developed for the conversion of γ-hydoxy enones into α-alkylidene-γ-butyrolactones. This one-pot method utilizes the Bestmann ylide (triphenylphosphoranylideneketene) and proceeds by way of acylation followed by an intramolecular conjugate addition/proton transfer/Wittig olefination sequence. The procedure is “base-free” and is useful for the preparation of a range
The Preparation of α-Alkylidene-γ-Butyrolactones Using a Telescoped Intramolecular Michael/Olefination (TIMO) Sequence: Synthesis of (+)-Paeonilactone B
作者:Michael G. Edwards、Martin N. Kenworthy、Russell R. A. Kitson、Alexis Perry、Mark S. Scott、Adrian C. Whitwood、Richard J. K. Taylor
DOI:10.1002/ejoc.200800558
日期:2008.10
A novel telescopedintramolecularMichael addition/proton transfer/HWE olefination sequence has been developed to provide rapid access to α-alkylidene-γ-butyrolactones. This methodology has been applied to prepare a range of tetrahydrobenzofuran-2,5-diones, and related systems, and also utilised in an extremely short synthesis of the natural product (+)-paeonilactoneB in enantiomerically pure form
Teaming up: The title reaction has been developed to deliver the product α‐alkylidene‐γ‐butyrolactones as single diastereomers with up to 98 % ee (see scheme; Ts=4‐toluenesulfonyl). The enantioselective process is catalyzed by 1, which contains both Lewis base and Brønsted acid moieties.
Design, Synthesis, and Application of a Chiral Sulfinamide Phosphine Catalyst for the Enantioselective Intramolecular Rauhut-Currier Reaction
作者:Xiao Su、Wei Zhou、Yangyan Li、Junliang Zhang
DOI:10.1002/anie.201500907
日期:2015.6.1
A novel class of chiral sulfinamide phosphine catalysts (Xiao‐Phos) are reported, which can be easily prepared from inexpensive commercially available starting materials. The Xiao‐Phos catalysts showed good performance in enantioselectiveintramolecular Rauhut–Currier reactions, generating α‐methylene‐γ‐butyrolactones in high yields with up to 99 % ee under mild conditions. Moreover, kinetic resolution