【摘要】 (1S,2S,3S,5S)-3-苄氧基-5-[6-苄氧基-2-[(三苯甲基)氨基]-9H-嘌呤-9-基]-2-[(苄氧基)甲基]环戊醇在碳酸氢钠作用下先被TEMPO/碘氧化,所得产物再与由镁/四氯化钛/二氯甲烷/THF形成的亚甲基化体系反应生成(1S,3R,4S)-N-(三苯甲基)-6-苄氧基-9-[[2-亚甲基-4-苄氧基-3-(苄氧基)甲基]环戊基]-9H-嘌呤-2-胺(4),在三氯化硼/甲醇/水的作用下脱除保护基制得恩替卡韦,总收率约44%。更多还原

【Abstract】 Entecavir was synthesized from(1S,2S,3S,5S)-3-benzyloxy-5-[6-benzyloxy-2-(tritylamino)9H-purin-9-yl]-2-(benzyloxymethyl)-cyclopentanol by oxidation with TEMPO/I2in the presence of NaHCO3,and methylenation with Mg/TiCl4/DCM/THF to give(1S,3R,4S)-N-triphenylmethyl-6-benzyloxy-9-[[2-methylene-4benzyloxy-3-(benzyloxy)methyl]cyclopentyl]-9H-purin-2-amine(4),which was subjected to deprotection with BCl3/ MeOH/H2O with an overall yield of about 44%.更多还原