Synthesis 2009(7): 1170-1174  
DOI: 10.1055/s-0028-1087971
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Efficient and Stereoselective Rearrangement of Baylis-Hillman Acetates Catalyzed by Gold(I) Chloride/Silver(I) Trifluoromethanesulfonate

Yunkui Liua, Dajie Maoa, Jianqiang Qiana, Shaojie Loua, Zhenyuan Xu*a, Yongmin Zhangb
a State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, 310014 Hangzhou, P. R. of China
Fax: +86(571)88320609; e-Mail: greensyn@zjut.edu.cn;
b Department of Chemistry, Zhejiang University, Xi-xi Campus, 310028 Hangzhou, P. R. of China
Further Information

Publication History

Received 24 October 2008
Publication Date:
24 February 2009 (online)

Abstract

Efficient and stereoselective rearrangement catalyzed by only one mole-percent gold(I) chloride/silver(I) trifluoromethanesulfonate of Baylis-Hillman acetates afforded 2-(acetoxymethyl)alk-2-enoates under mild reaction conditions in good to high yields with 100% E-selectivity. For cyclohex-2-enone-derived Baylis­-Hillman acetates, the reaction gave 2-alkylidenecyclohex-3-enones in good yields.

22

A referee commented that the loss of 1,3-diaxial repulsion between the methoxycarbonyl or R group and the acetal oxygens may be another factor why intermediate 7 is not destabilized so much (see Scheme  [5] ).