Lewis acid mediated reactions of cyclopropyl aryl ketones with alpha-ketoesters: facile preparation of 5,6-dihydropyran-2-ones.
[reaction: see text] A new general method for the synthesis of 5,6-dihydropyran-2-ones from cyclopropyl aryl ketones (monoactivated cyclopropanes) and alpha-ketoesters in good to excellent yields has been developed. The process involves a cascade of reactions, including a nucleophilic ring-opening reaction of monoactivated cyclopropane by H2O, Lewis acid mediated transesterification, and an aldol type reaction.
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