SnCl4-Mediated Reactions of Cyclopropyl Alkyl Ketones with α-Keto Esters
作者:Yong-Hua Yang、Min Shi
DOI:10.1002/ejoc.200600618
日期:2006.12
to good yields with good stereoselectivitiesvia the sequential nucleophilic ring-opening reaction of cyclopropane by H2O, aldol type reaction and subsequent cyclic transesterification mediated by the Lewis acid. The mechanism was further confirmed by introducing a substituent at the other α-position of the cyclopropyl alkyl ketone to produce two or three other products without the formation of spiro-γ-lactone
A Stereoselective Synthetic Route to 1,6-Dioxaspiro[4.4]non-3-en-2-ones from Cyclopropyl Alkyl Ketones and α-Ketoesters
作者:Yong-Hua Yang、Min Shi
DOI:10.1021/ol060415a
日期:2006.4.1
The SnCl4-mediated reactions of cyclopropyl alkyl ketones with alpha-ketoesters afford a novel method for the synthesis of 1,6-dioxaspiro[4.4]non-3-en-2-ones with high stereoselectivities in moderate to good yields. This process is a sequential reaction involving a nucleophilic ring-opening reaction of the cyclopropane by H2O, an aldol-type reaction, and a cyclic transesterification mediated by Lewis acid.