desulfonylation upon acetolysis of the oxathiazinane ring to give 43 in good yield. The amine obtained by selective removal of the Cbz group of the alcohol 44 was reacted with MeSC(═O)-l-Val-O-t-Bu (38) to provide 45, which was oxidized to the carboxylic acid 46. Reaction of 46, isonitrile 51, isovaleraldehyde, and 2,4-dimethoxybenzylamine furnished the desired Ugi products, the final deprotection of which successfully
描述了(-)-muraymycin(MRY)D2及其差向异构体(抗菌核苷
天然产物)的第一个全合成的完整细节。该方法的关键战略要素包括
尿素二肽部分的制备在含有所述muraymycins发现升-外延-capreomycidine经由所述
氨基磺酸酯的氮宾C-H插入10通过的Ugi 4和所述完全受保护muraymycin骨架在后期阶段-组分反应。因此,将
氨基磺酸盐10与10 mol%的Rh 2(esp)2催化剂的
丁腈CH插入,以47%的收率得到环状
氨基磺酸盐11a和11b(11a:11b= 1:2.0)。环状
胍骨架的构建是通过HgBr 2促进的42的环化作用,然后在草ath嗪烷环的乙酰化作用下进行脱磺酰作用而得到的,从而以良好的收率得到43。通过选择性去除Cbz基团的醇的的得到的胺44用
MESC(= O)反应-升-Val-O-吨-Bu(38),以提供45,将其氧化为
羧酸46。反应46,异腈51,
异戊醛和2