By the action of liquid ammonia, the cyclpadducts of isothiocyanates with 3, 4-dimethyl-5-(2-hydroxy) ethylthiazolium ylides (Ia-b) are converted into spiro [3, 3a-dimethylperhydrofuro [2, 3-d] thiazole-2, 4'-(5'-iminoimidazolidine)] derivatives (IIa-b), while the reactions of liquid ammonia with N-benzyl analogues (Ic-e) afford 3-aryl-6, 8-dimethyl-2, 9-dithia-4, 6, 8-triazatricyclo [3, 3, 0, 11, 5] oct-3-enes (IIIa-c) involving an unusual base-catalyzed cleavage reaction of the fused spiro thiazolidine ring. A possible mechanism of the novel transformation reaction is suggested.
在液
氨的作用下,异
硫氰酸酯与 3,4-二甲基-5-(2-羟基)乙基
噻唑啉(Ia-b)的环padducts 转化为螺[3,3a-二甲基全氢
呋喃[2,3-d]
噻唑-2,4'-(5'-亚
氨基
咪唑烷)]衍
生物(IIa-b)、而液
氨与 N-苄基类似物(Ic-e)的反应则产生了 3-芳基-6,8-二甲基-2,9-二
硫杂-4,6,8-三氮杂
三环 [3,3,0,11,5] 辛-3-烯(IIIa-c),其中涉及融合螺
噻唑烷环的不寻常碱催化裂解反应。本文提出了这种新型转化反应的可能机理。