| 摘要 |
(-)-Cis-4-amino-1- (2-hydroxymethyl-1,3 -oxathiolan-5-yl)-(1H)- pyrimidin-2-one (I) and its derivs. are new. (I) contg. max. 5 wt% of (+)-enantiomer (pref. below 1 wt%) is also claimed. (I) is prepd. by sepn. from a racemic mixt., preferably by chiral HPLC. The stationary phase used is preferably beta-cyclodextrin or cellulose triacetate. Alternatively sepn. is by enzyme-mediated enantioselective catabolism, preferably using an immobilised enzyme. The enzyme is preferably cytidine deaminase or a 5-nucleotidase. |
