Reactions of Diels–Alder adducts of a sugar-derived dihydropyranone leading to fused polycyclic compounds
作者:Christian A. Iriarte Capaccio、Oscar Varela
DOI:10.1016/j.carres.2004.01.008
日期:2004.4
having three or four fused rings. Reduction of the carbonyl group of the butadiene adduct (2) took place with low facial selectivity affording the alcohols 5 and 6 in 1:1.4 ratio. In contrast, a higher diastereoselection was observed for the reduction of the carbonyl of the cyclopentadiene adducts 3 and 4 to give the endo alcohols 10 and 13, respectively. The epoxidation of 6 showed low facial selectivity
操纵从光学活性(ee> 86%)(S)-2-苄基-2H-吡喃-3(6H)-一(1)衍生的环加合物2、3和4的酮和烯烃官能团具有三个或四个稠环的多环系统。丁二烯加合物(2)的羰基的还原具有低的面部选择性,从而以1∶1.4的比例得到醇5和6。相反,观察到较高的非对映选择性,以还原环戊二烯加合物3和4的羰基,分别得到内醇10和13。6的环氧化在形成层7和8中显示出较低的面部选择性,而10和13的环氧化发生在降冰片烯系统的外表面,通过自发地通过分子内攻击打开环氧化物,自发生成多环醇11和14。吡喃环的羟基。