作者:Yutaka Nishimura、Kenji Mori
DOI:10.1002/(sici)1099-0690(199802)1998:2<233::aid-ejoc233>3.0.co;2-m
日期:1998.2
(−)-Frontalin [(1S,5R)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]- octane (1)] was synthesized from ethyl 2-oxocyclopentane-1-carboxylate (2) as the starting material. Baker′s yeast was used for the asymmetric reduction of 2 to 3. The S configuration at C-1 of 1 was generated by diastereoselective methylation of the dianion derived from 3 to give 4. The present process furnished about 10 g of 1 with enantiomeric
(-)-Frontalin [(1S,5R)-1,5-二甲基-6,8-二氧杂双环[3.2.1]-辛烷 (1)] 是由 2-氧代环戊烷-1-羧酸乙酯 (2) 合成的起始材料。面包酵母用于不对称还原 2 到 3。1 的 C-1 处的 S 构型是通过衍生自 3 的二价阴离子的非对映选择性甲基化产生的,得到 4。本方法为约 10 g 的 1 提供对映异构体纯度 89.1% ee