Supported synthesis of tri α(1,2) Mannosides: 2-O-p-cyanobenzoate as an efficient protecting group

A self-supported synthesis of an α(1 → 2)-linked trimannoside has been developed using a divalent glycosyl acceptor. Among the tested options, the 2-O-(p-cyanobenzoyl) group proved to be an effective participating and protecting group, particularly when used in combination with amide linkers for attachment to the support. Based on these findings, we propose a new mannosyl donor, methyl tert-butylphenyl 2-O-(p-cyanobenzoyl) 3,4,6-tri-O-benzyl-1-thio-α-D-mannopyranoside, which combines excellent reactivity in glycosylation with facile deprotection and compatibility with amide based self-supported strategies.