Pyrroles as terminators in cationic cyclizations. The preparation of 5, 6, 7, 8-tetrahydroindolizidines and 6, 7, 8, 9-tetrahydro-5H-pyrrolo [1, 2-a] azepines
SP Tanis, JW Raggon
文献索引:Tanis, Steven P.; Raggon, Jeffrey W. Journal of Organic Chemistry, 1987 , vol. 52, # 5 p. 819 - 827
N-(Epoxyalky1) pyrroles 8-13 are readily prepared either by direct pyrrole N-alkylation with either w-iodo epoxides or w-iodo-l, 2-alkanediol acetonides followed by conversion to the corresponding epoxides. The cyclizations of these N (epoxyalky1) pyrroles were examined with a range of Lewis acids providing cyclized products 14 and 16-21 in moderate to excellent yields. The cyclization products 14, 16, and 20 are formally the products of" anti- ...