Studies towards a new one-pot heterocyclization: ButOK-promoted oxa- and aza-Michael addition–intramolecular carbocyclization of prop-2-ynyl alcohols and amines with α,β-disubstituted nitroalkenes

Abstract

ButOK-promoted reaction of prop-2-ynyl alcohols 5 or N-methylprop-2-ynylamine 12 with nitroalkenes 1–4 affords 3-methylenetetrahydrofurans 6–9 and 3,4-dihydropyrans 10 and 11 or 3-methylenepyrrolidines 13–16, respectively, in moderate to good yields, with total allylic 1,3-strain-controlled diastereoselectivity.