Reactions of 4-tert-butyl-5-methylene-3,3-dimethyl-Δ1-1,2,4-triazoline with dimethyl acetylenedicarboxylate

Abstract

4-tert-Butyl-5-methylene-3,3-dimethyl-Δ1-1,2,4-triazoline (1) reacts rapidly with dimethyl acetylenedicarboxylate (2) to afford dienamines 3 and 4 from Michael addition and enamine 5 by extensive skeletal rearrangement. Assignments of their structures and probable mechanisms of their formation are discussed.