Direct and stereoselective synthesis of β-D-mannosides using 4,6-O-benzylidene-protected mannosyl diethyl phosphite as a donor

[摘要] A direct and practical method for the construction of beta-mannosidic linkages is described. While beta-selectivities in the TMSOTf-promoted glycosidation of 2,3,4,6-tetra- O-benzyl -(D)- man nosy I diethyl phosphite are found to be highly dependent on the reactivity of acceptor alcohols, 2,3-di-O-benzyl-4,6-O-benzylidene-(D)-mannosyl diethyl phosphite reacts with a wide range of acceptor alcohols in the presence of TMSOTf in CH2Cl2 at -45 degrees C to give beta-mannosides in high yields with good to high beta-selectivities. (c) 2005 Elsevier Ltd. All rights reserved.

[发布日期] 2005-11-07

[关键词] 4,6-O-benzylidene acetal;mannosyl diethyl phosphite;beta-selective glycosidation