顺式-和反式-2,5-二取代四氢呋喃的立体选择性合成  

Stereoselective Synthesis of cis- and trans-2,5- Disubstituted Tetrahydrofurans

作　　者：史鸿鑫[1] 刘化章[1] Bloch R. Mandville G. 林辉[3] 

机构地区：[1]浙江工业大学化工学院 [2]Université de Paris-Sud,ICMO.91405 Orsay Cédex,France [3]浙江大学理学院化学系

出　　处：《高等学校化学学报》2003年第5期831-836,共6页Chemical Journal of Chinese Universities

基　　金：中法政府科技合作课题(批准号:1996-4)资助

摘　　要：内酯与有机锂试剂发生亲核加成反应,再在酸催化下用NaBH_3CN还原,反应的立体选择性可能是由氢负离子在中间体氧鎓离子位阻最小的一侧进攻所引起.所得的三环化合物经热分解和加氢反应,制备顺式和反式-2,5-二取代四氢呋喃。A general route to either cis- or trans -2,5-disubstituted tetrahydrofurans was described by using the nucleophilic addition of organolithium derivatives to tricyclic lactones, followed by a highly stereocon-trolled acid-assisted reduction with sodium cyanoborohydride of the hemiketals formed. The stereoselec-tivity observed can be rationalized by the preferential approach of the hydride on the less hindered face of an oxonium ion intermediate. The cis- or trans-2, 5-disubstituted tetrahydrofurans were provided by the hot decomposition and then hydrogenation of tricycle compounds produced.

关 键 词：顺式-2 5-二取代四氢呋喃 反式-2 5-二取代四氢呋喃 立体选择性合成 内酯 有机锂试剂 亲核加成反应 酸催化还原 aBH2CN 拮抗血小板活化因子作用 

分 类 号：O626.11[理学—有机化学] TQ463.53[理学—化学]