An efficient synthesis of C- and N-nucleosides has been developed in an enantioselective and stereocontrolled manner starting from Diels-Alder adduct of furan and dimethyl acetylenedicarboxylate by chemicoenzymatic strategy. The symmetric unsaturated dimethyl esters 2 and 3 were almost quantitatively hydrolysed with pig liver esterase to yield half-esters 4 and 5 with reasonably high optical yields.
                                    从
呋喃和乙酰二
羧酸二甲酯的Diels-Alder加合物开始,通过
化学酶策略,以对映选择性和立体控制方式开发了C-和N-核苷的有效合成方法。对称不饱和二甲基酯2和3用猪肝
酯酶几乎定量
水解,得到半酯4和5,具有相当高的光学收率。手性半酯4的脱羧
臭氧分解,然后进行
化学转化,得到甲基
L-核糖苷12,但对映异构体转化后(4至13和5至28)从13中获得甲基
D-核糖苷(17),(+)-Showdomycin(22)和(-)-6-氮杂双胍(27),从28中获得(-)-cordycepin(32)。