A One-Pot Organometallic Route from a 4-Alkenylpyridine to a 4,4-Spiro-Linked Ethyl 1,4-Dihydropyridine-1-carboxylate
作者:Gideon Fraenkel、Albert Chow、Yulan Liang、Jinhua Song、Judith Gallucci
DOI:10.1002/hlca.201200373
日期:2012.11
one‐pot process without isolation of intermediates, (but‐3‐en‐1‐yl)pyridine (13) is treated sequentially with dicyclohexylborane, trimethylaluminium, and ethyl carbonochloridate yielding ethyl 1,4‐dihydro‐4,4‐(tetramethylene)pyridine‐1‐carboxylate (=ethyl 8‐azaspiro[4.5]deca‐6,9‐diene‐8‐carboxylate; 2) in 46% yield based on starting alkenylpyridine 13 (Scheme 5).
在不分离中间体的单锅法中,依次用二环己基硼烷,三甲基铝和碳氯酸乙酯处理(3-烯-1-基)吡啶(13),得到乙基1,4-二氢-4,4-(基于起始的烯基吡啶13(方案5),四亚甲基)吡啶-1-羧酸盐(= 8-氮杂螺[4.5]癸-6,9-二烯-8-羧酸乙酯; 2)的产率为46%。