作者:Osamu Tamura、Takehiko Yanagimachi、Hiroyuki Ishibashi
DOI:10.1016/s0957-4166(03)00530-5
日期:2003.10
Treatment of radical precursor 15a having a vinyl sulfide moiety with Bu3SnH in the presence of AIBN in boiling benzene afforded exclusively the 6-exo cyclization product 16a, whereas similar treatment of the exo-methylene compound 15b gave a mixture of the 6-exo cyclization product 16b and the endo-olefin product 17 formed by a 1,5-hydrogen shift. Based on these findings, the synthesis of (-)-aphanorphine was achieved using a sulfur-directed 6-exo-selective aryl radical cyclization of 22. (C) 2003 Elsevier Ltd. All rights reserved.