α-Homomannojirimycin (1) and 6-epi-homomannojirimycin (2) are each synthesized from 2-azido-2-deoxy-3,4:6,7-di-O-isopropylidene-D-glycero-D-talo-heptono-1,5-lactone (3) in which the side chain acetonide is hydrolyzed to give the corresponding diol which is then protected with a silyl protecting agent to form a silyl ether. The latter compound is used as a divergent intermediate in which the piperidine ring is formed by joining the nitrogen function at C-2 to C-6 (A) with inversion of configuration at C-6 to form 6-epi-homomannojirimycin or (B) with retention of configuration at C-6 to form α-homomannojirimycin.
α-高甘露尻霉素(1)和 6-表高甘露尻霉素(2)分别由 2-
叠氮-2-脱氧-3,4:6,7-二-O-异亚丙基-D-
甘油-D-卤代-庚-1,
5-内酯(3)合成,其中侧链
丙酮水解后得到相应的二元醇,然后用
硅烷保护剂保护形成
硅烷醚。后一种化合物可用作发散中间体,其中的
哌啶环是通过将 C-2 位的氮功能连接到 C-6 位形成的(A),C-6 位的构型发生反转,形成 6-epi-homannojirimycin;或(B)C-6 位的构型保持不变,形成 α-homannojirimycin。