| 摘要 |
PURPOSE:To produce stereoselectively and in a high yield a cyclooligomannose comprising 5-8 alpha-1,4-linked mannose units by removing the protective group of a specific compound. CONSTITUTION:A compound of formula IV obtained by the condensation of a compound of formula I [wherein R<1> is a group of formula II; R<2> is toluoyl; R<3> is (methoxy) benzyl; R<4> is monochloroacetyl; and m is 1-7] with a compound of formula III (wherein X is -SCH3, F or allyoxy; and n is 1-7 with m+n being 5-8) is demonochloroacetylated to produce a compound which corresponds to a compound of formula IV wherein R<4> is H. The resulting compound is ethoxyethyl-etherified to produce a compound of formula IV wherein R<4> is an ethoxyethyl group, which is then detoluoylated to produce a compound which corresponds to a compound of formula IV wherein R<2> is H and R<4> is an ethoxyethyl group. The resulting compound is (methoxy)benzylated to produce a compound of formula IV wherein R<2> is (methoxy)benzyl and Ru4 is an ethoxyethylether group, which is then deethoxyethylated to produce a compound of formula IV wherein R<2> of (methoxy)benzyl and R<4> is H. The resulting compound is cyclized in the presence of a glycosylation catalyst to produce a compound of formula V (wherein R<3> is R<4>), and the protective group of the produced compound is removed to produce a compound of formula VI (wherein R is H or benzyl). |
