A stereoselective synthetic route to 1,6-Dioxaspiro[4.4]non-3-en-2-ones from cyclopropyl alkyl ketones and alpha-ketoesters.
[reaction: see text] The SnCl(4)-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 H(2)O, an aldol-type reaction, and a cyclic transesterification mediated by Lewis acid.
Yang
Yong-Hua
YH
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, China.
Shi
Min
M