Racemic Feist's acid is treated with (R)-(+) -.alpha.-methylbenzylamine to yield (1R-trans)-3-methylene -cyclopropane-1,2-dicarboxylic acid, (R)-.alpha.-methylbenzyl-amine (1:1) salt. This salt can then be converted to (1R-trans)-3-methylene-1,2-cyclopropanedicarboxylic acid, dimethyl ester which is an intermediate in the preparation of the antiviral agent [1R-(1.alpha.,2.beta.,3.alpha.)]-2-amino-9-[2,3-bis(hydroxymethyl)cyclobut yl]-1,9-dihydro-6H-purin-6-one. The improved process also enables the recovery of racemic Feist's acid from the resolution.
混合型的费斯特酸与(R)-(+)-α-甲基
苄胺反应,生成(1R-trans)-3-甲烯基-
环丙烷-1,2-二
羧酸,以及(R)-α-甲基
苄胺(1:1)盐。该盐可以转化为(1R-trans)-3-甲烯基-
1,2-环丙烷二羧酸二甲酯,这是制备抗病毒药物[1R-(1α,2β,3α)]-2-
氨基-9-[2,3-双(羟甲基)
环丁基]-1,9-二氢-
6H-嘌呤-6-酮的中间体。改进的工艺还可以从分离中回收混合型费斯特酸。