Weinreb Amide based building block for convenient access to vinyl ketones

A new strategy for the synthesis of vinyl ketones has been achieved. Hitherto unknown and easily accessible, β-phenylseleno-N-methoxy-N- methylpropanamide, obtained through two simple reactions, served as a building block for convenient access to vinyl ketones. The N-methoxy-N-methyl amide moiety ensured no overaddition of the Grignard reagent and, hence, the excellent formation of β-phenylseleno ketones; oxidative work-up with hydrogen peroxide provided ready access to the vinyl ketones with concomitant loss of phenylselanol. © Georg Thieme Verlag Stuttgart · New York.