摘要:
9- beta- D -Arabian ofuranosyl guanine (6) and 2-amino-9-(beta-D-arabianofuranosyl)purine (8) were prepared from 2-amino-6-chloro-9-(2,3,5-triphenylmethoxyl-p-D-arabianofuranosyl)purine (4), a key intermediate which was stereoselectively prepared from 2,3,5-triphenylmethoxyl-D-arabianofuranose and 2-amino-6-chloro-purine. The yield of the intermediate was obviously improved and only P-isomer was formed by using the activated molecular sieve as environmental friendly catalyst, overcoming the defect that a 1: 1 mixture of alpha- and beta-isomers was formed, which was difficult to separate, when toxic mercury cyanide was previously used as catalyst. (C) 2004 Elsevier Ltd. All rights reserved.