Holla, B Shivarama; K, Shridhara; Kalluraya, Balakrishna, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1991, vol. 30, # 7, p. 672 - 675
Holla, B Shivarama; K, Shridhara; Kalluraya, Balakrishna, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1991, vol. 30, # 7, p. 672 - 675
A new Michael-initiated cyclopropanation reaction using alpha-bromochalcones as Michael acceptor was developed. Compared to previous works using arylidenemalonates as Michael acceptor, this novel protocol could improve the synthesis of trans-isomers of diethyl 2-benzoyl-3-phenyl-cyclopropane-1,1-dicarboxylates. More importantly, this method also provided the first access to the cis-isomers of these densely substituted cyclopropanes with the Michael-initiated ring closure (MIRC) strategy, albeit with a poor diastereoselectivity. (C) 2013 Published by Elsevier Ltd.