A NOVEL SYNTHESIS OF SPIRO 1,3-DITHIIN AND SPIRO 1,3-THIAZINE DERIVATIVES UNDER PHASE TRANSFER CATALYSIS (PTC) CONDITIONS
作者:Ahmed M. M. El-Saghier
DOI:10.1080/10426500490468065
日期:2004.7.1
Ketene S,S-acetals 1a,b or ketene N,S-acetals 2a,b reacts in situ with a variety, of ylidenemalononitriles to afford the desired spiro [1,3]dithiin, heterocycles 3ab-11a,b or spirol[1,3]thiazine heterocycles 12a,b-20a,b. Treatment of 2-(1-acetyl-2-oxopropyliedene)spiro[1,3]thiazine derivatives 13b, 17d, and 18d with malononitrile afforded the corresponding dispiro heterocycles 21, 22, and, 23.