Diastereoselective synthesis of tricyclo[3.2.1.02,7]octanes; chiral building blocks for terpenes
作者:Norbert A. Braun、Iris Klein、Dietrich Spitzner、Bernhard Vogler、Horst Borrmann、Arndt Simon
DOI:10.1016/0040-4039(95)00601-8
日期:1995.5
One pot cascade reactions of 3-benzyloxy-cyclohex-2-enone (1) with tert-butyl-(Z)-(+)-2-chloro-3-[(4S)-2,2-dimethyl-1,3-dioxolan-4-yl]-2-propenoate (2) lead to (1S;2R;5S;7S;8R;4′S)-tert-butyl-2-benzyloxy-8-(2′,2′-dimethyl-1′,3′-dioxolan-4′-yl)-6-oxo-tricyclo[3.2.1.02,7]octane-1- carboxylate (3) and with (E)-(+)-2 to (1R;2S;5R;7R;8S;4′S)-4. The tricyclic compounds 3 and 4 were formed with high diastereomeric
3-苄氧基-环己-2-烯酮(1)与叔丁基-(Z)-(+)-2-氯-3-[(4 S)-2,2-二甲基-1, 3-二氧戊环-4-基] -2-丙酸酯(2)导致(1 S ; 2 R ; 5 S ; 7 S ; 8 R ; 4 'S)-叔丁基-2-苄氧基-8-(2 ′,2′-二甲基-1′,3′-二氧戊环-4′-基)-6-氧代三环[3.2.1.0 2,7 ]辛烷-1-羧酸酯(3),并带有(E)-(+ )-2至(1R; 2S; 5R; 7R; 8S; 4'S)-4 。三环化合物3和4 形成的非对映异构体过量很高。