Michael additions of thiocompounds to α,β-unsaturated carbonyl compounds in aqueous media: Stereoselectivity with unambiguous characterization by NMR

Abstract

The reactions of crotonaldehyde (8) with thiophenol (2) and benzalacetone (10) with ethane-1,2-dithiol (11) yield Michael addition products. The reactions of thiophenol (2) with (R)-carvone (13) and (S)-perillaldehyde (15) lead to (2S,3R,5S)-5-isopropenyl-2-methyl-3-(phenylthio)cyclohexanone (14) and (1R,2R,4S)-4-isopropenyl-2-(phenylthio)cyclohexanecarbaldehyde (16), respectively. An unambiguous elucidation of the stereochemistry of 14 and 16 by NMR is also presented. ©2008 Sociedade Brasileira de Química.