[structure: see text] An efficient chemoenzymatic process is described for the synthesis of pelitrexol, a novel GARFT inhibitor. The remoteness of this molecule's stereocenter in the tetrahydropterin moiety from the terminal carbonyl group provided a significant challenge in synthesis. The introduction of an oxalamic ester adjacent to the stereocenter dramatically enhanced an enzyme's enantioselectivity for hydrolysis at the terminal ester, producing the desired S-acid with high optical purity and yield. The recycling of the "wrong" enantiomer is achieved via a dehydrogenation/hydrogenation strategy.

中文翻译：

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通过远程立体中心的酶促分化有效地合成派瑞特罗的化学酶促反应。

[结构：见正文]描述了一种有效的化学酶促方法，用于合成新型GARFT抑制剂派力曲索。该四氢蝶呤部分中该分子的立体中心距末端羰基的距离较远，这为合成带来了重大挑战。在立构中心附近引入草酰胺基酯极大地增强了酶在末端酯上水解的对映选择性，从而以高的光学纯度和产率产生了所需的S-酸。“错误的”对映异构体的再循环是通过脱氢/氢化策略实现的。