Synthesis of (-) swainsonine and intermediate compounds employed in such
申请人:——
公开号:US05187279A1
公开(公告)日:1993-02-16
(-)-Swainsonine is prepared by the steps of first reacting a compound having the formula: ##STR1## wherein each R.sub.2 is lower alkyl, with (4-carbalkoxybutyl) triphenylphosphonium bromide in a strong base to obtain an alcohol having the formula: ##STR2## wherein R.sub.2 is as defined above and R is C.sub.1 -C.sub.8 alkyl; the alcohol is then reacted with methanesulfonyl chloride or p-toluenesulfonyl chloride or benzenesulfonyl chloride in the presence of a tertiary amine to obtain the corresponding sulfonate. Heating the sulfonate with an azide in an organic solvent yields an imine having the formula: ##STR3## wherein R.sub.2 and R are ad defined above. Treating the imine with an inorganic base, in aqueous alcohol provides upon acidification, the corresponding acid. Heating the acid at reflux temperature in organic solvent, yields an enamide having the formula: ##STR4## wherein R.sub.2 is as defined above. Treating the enamide with diborane followed by reaction with hydrogen peroxide provides a protected swainsonine having the formula: ##STR5## which upon acid hydrolysis gives swainsonine.
Scale-Up Synthesis of Swainsonine: A Potent α-Mannosidase II Inhibitor
作者:Pradeep K. Sharma、Rajan N. Shah、Jeremy P. Carver
DOI:10.1021/op800059y
日期:2008.9.19
The large-scale synthesis of Swainsonine 1, a potentα-mannosidase II inhibitor, has been achieved with several improvements. The key modifications were (a) performing the Wittig olefination under mild conditions and isolation of the product 4 with modified workup conditions, (b) introduction of the azido group on a large scale under Mitsunobu conditions to produce 12, (c) performing the 1, 3-dipolar