Selective transformations of differently functionalized 4-ethynyl-octa-1,7-dienes and 5-ethynyl-nona-1,8-dienes via intramolecular Pauson–Khand reaction: preparation of new and useful building blocks for the synthesis of angularly fused triquinanes
作者:José Marco-Contelles、Juliana Ruiz-Caro、Emily Mainetti、Priscille Devin、Louis Fensterbank、Max Malacria
DOI:10.1016/s0040-4020(01)01209-1
日期:2002.2
the regiochemistry of the PK reaction, affording major bicyclo derivatives 33 and 34 (in a 4.6:1 ratio, the major isomer (33) having the free hydroxyl group cis to the methyl group at C-6a), and compound 35 with the hydroxyl group trans to proton H-6a at ring junction. All new adducts are potential useful building blocks for the total synthesis of angularly fused triquinanes.
4-溴甲基二甲基甲硅烷氧基-4-乙炔基-6,6-二甲基辛-1-烯-7-炔(1)分子内的Pauson-Khand(PK)反应(不同功能化的4-乙炔基-辛基-1,7-二烯(2 - 6)和5-乙炔基-5-羟基-2,4,4-三甲基-壬-1,8-二烯(7)被报告。将得到的双环[3.3.0]辛-1-烯-3-酮(22 - 29)和(33 - 35)已经以良好的收率获得,具有适度的立体选择性。主要异构体(22,24,26,28)具有与游离的或保护的羟基基团的顺式H-6a的稠环碳原子。在二烯炔化合物7中,两个烯基链长度相同的宝石-二甲基官能团决定了PK反应的区域化学,提供了主要的双环衍生物33和34(以4.6:1的比例,主要的异构体(33)具有游离的羟基在C-6a处顺式为甲基,并且具有羟基的化合物35在环结处反式为质子H-6a。所有新的加合物都是潜在的有用的结构单元,可以用于角熔融三喹烷的全合成。