Intramolecular Cyclization of β-Alkynylpropanamides to γ-Alkylidene-γ-butyrolactams
摘要:
A general method for the base-catalized intramolecular cyclization of beta-alkynylpropanamides 1 to gamma-alkylidene-gamma-butyrolactames 2 (and 3) was established. Reactions of beta-alkynylamides 1c-h, possessing alkyl groups at the terminal acetylenes, in the presence of a catalytic amount of LiN(TMS)(2)/AgOTf (= 2:1) in toluene gave exclusively (Z)-alkylidenelactames 2c-h in good yields. (C) 1998 Elsevier Science Ltd. All rights reserved.