one-step ‘ring switching’ transformation of (S)-3-[(dimethylamino)methylidene]-5-(methoxycarbonyl)tetrahydrofuran-2-one (4) with 2-pyridineacetic acid derivatives (5–7) and 2-aminopyridines (8, 9) afforded the corresponding 3-(4-oxo-4H-quinolizinyl-3)- (15–17) and 3-(4-oxo-4H-pyridino[1,2-a]pyrimidinyl-3)-2-hydroxypropanoates (18, 19), respectively.
(S)-3-[(二甲基
氨基)亚甲基] -5-(甲氧羰基)
四氢呋喃-2-酮(4)与2-
吡啶乙酸衍
生物(5-7)和2-的一步式“环交换”转化
氨基吡啶(8,9)提供相应的3-(4-oxo-4 H -quinolizinyl-3)- (15-17)和3-(4-oxo-4 H -pyridino [1,2- a ]
嘧啶基- 3)-2-羟基
丙酸酯(18、19)。