SYNTHESIS OF A FULLY PROTECTED GLYCOOCTAOSYL SERINE ISOLATED FROM BLOOD GROUP A HUMAN OVARIAN MUCIN

摘要

N-(9-Fluorenylmethoxycarbonyl)-O-{[O-(2-acetamido-3,4,6-tri-O-acetyl-2-deo xy-alpha-D-galactopyranosyl)-(1 --> 3)-O-[(2,3,4-tri-O-benzyl-alpha-L-fucopyranosyl)-(1 --> 2)]-O-(4,6-di-O-acetyl-beta-D-galactopyranosyl)-(1 --> 3)-O-(3,6-di-O-benzyl-2-deoxy- 2-phthalimido-beta-D-glucopyranosyl)-(1 --> 6)]-O-[(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-alpha-D-galactopyranosyl)-( 1 --> 3)-O-[(2,3,4-tri-O-benzyl-alpha-L-fucopyranosyl)-(1 --> 2)]-O-(4,6-di-O-acetyl-beta-D-galactopyranosyl)-(1 --> 3)]-2-acetamido-2-deoxy-alpha-D-galactopyranosyl}-(1 --> 3)-L-serine allyl ester, a protected glycosylserine identified as a blood group A mucin-type determinant, was synthesized for the first time in an efficient and stereocontrolled manner. Ethyl O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-alpha-O-galactopyranosyl-(1 --> 3)-O-[(2,3,4-tri-O-benzyl-alpha-L-fucopyranosyl)-(1 --> 2)]-O-(4,6-di-O-acetyl-beta-D-galactopyranosyl)-(1 --> 3)-3,6-di-O-benzyl-2-deoxy-2-phthalimido-1-thio-beta-D-glucopyranoside and N-(9-fluorenylmethoxycarbonyl)-O-{O-(2-acetamido-3,4,6-tri-O-acetyl-2-deox y-alpha-D-galactopyranosyl -(1 --> 3)-O-[(2,3,4-tri-O-benzyl-alpha-L-fucopyranosyl)-(1 --> 2)]-O-(4,6-di-O-acetyl-beta-D-galactopyranosyl)-(1 --> 3)-2-acetamido-2-deoxy-alpha-D-galaclopyranosyl}-(1 --> 3)-L-serine allyl ester were the key intermediates for the crucial glycosylation to afford the title compound. [References: 19]