The multi-protected compounds 4 and 5 were treated with 20% iodine in methanol to give 1,4-dideoxy-1,4-imino-D-arabinitol 1 and 1,4-dideoxy-1,4-imino-L-xylitol 2 directly. Iodine was an efficient catalyst for deprotection of O-isopropylidene, O-(tert-butyldimethylsilyl), N-(9-phenylfluoren-9-yl) and N-benzyloxycarbonyl groups, resulting in intramolecular cyclisation.
经多重保护的化合物4和5,以20%
碘的
甲醇溶液处理,直接生成1,4-二去氧-1,4-
亚胺基-
D-阿拉伯糖醇1和1,4-二去氧-1,4-
亚胺基-
L-木糖醇2。
碘作为高效的催化剂,能够去除O-异丙叉、O-(叔丁基二甲基
硅基)、N-(
9-苯基芴-9-基)和
N-苄氧羰基等保护基团,从而实现分子内环化。