1987 年 45 巻 7 号 p. 682-690
New syntheses of a variety of heterocycles using two kinds of ketene-S, N-acetals (KSNA) are described. KSNA derived from thioamides are regarded as interesting enamines (A : α-alkylthioenamines B : lithioenamines). Their utilities as synthetic intermediates to heterocycles are presented.