A new strategy in enantioselective intramolecular hetero Diels–Alder reaction: catalytic double asymmetric induction during the tandem transetherification–intramolecular hetero Diels–Alder reaction of methyl (E)-4-methoxy-2-oxo-3-butenoate with rac-6-methyl-5-hepten-2-ol
作者:Hidetaka Koga、Eiji Wada
DOI:10.1016/s0040-4039(02)02706-5
日期:2003.1
An efficient catalytic double asymmetric induction during the tandem transetherification–intramolecular hetero Diels–Alder reaction has been developed. The enantioselective tandem reaction of methyl (E)-4-methoxy-2-oxo-3-butenoate with rac-6-methyl-5-hepten-2-ol has been achieved to provide methyl (2R,4aS,8aR)-3,4,4a,8a-tetrahydro-2,5,5-trimethyl-2H,5H-pyrano[4,3-b]-pyran-7-carboxylate in good yield
已经开发了一种在串联跨醚化反应-分子间杂狄尔斯-阿尔德反应中有效的催化双不对称诱导作用。(E)-4-甲氧基-2-氧代-3-丁烯酸甲酯与rac -6-甲基-5-庚烯-2-醇的对映选择性串联反应可提供甲基(2 R,4a S,8a R)-3,4,4a,8a-四氢-2,5,5-三甲基-2 H,5 H-吡喃并[4,3- b ]-吡喃-7-羧酸盐,具有良好的动力学分辨率(最高可达在(S,S)-存在下,高非对映选择性(高达92%de)和高对映选择性(高达97%ee )-叔-Bu-双(恶唑啉)-Cu(SbF 6)2和5Å分子筛。