ABSTRACT
Experimental Methods ........................................................................................... 115 General Methods ............................................................................................... 115 General Procedure ............................................................................................. 115
2-Trimethylsilylethyl 4,6-O-Benzylidene-2-Deoxy-2-(2,2,2Trichlorethoxycarbamido)-β-d-Glucopyranoside (1) ................................... 115 2-Trimethylsilylethyl 2-Amino-2-N-Benzyl-4,6-O-Benzylidene-2,3N,O-Carbonyl-2-Deoxy-β-d-Glucopyranoside (2) ....................................... 116 Phenyl 4,6-O-Benzylidene-2-Deoxy-1-Thio-2-(2,2,2Trichlorethoxycarbamido)-β-d-Glucopyranoside (3) ................................... 116 Phenyl 2-Amino-2-N-Benzyl-4,6-O-Benzylidene-2,3-N,O-Carbonyl-2Deoxy-1-Thio-β-d-Glucopyranoside (4) ...................................................... 117 Phenyl 2-Amino-4,6-O-Benzylidene-2,3-N,O-Carbonyl-2-Deoxy-2-N-(4-Nitrobenzyl)-1-Thio-β-d-Glucopyranoside (5) ....................................... 117 Phenyl 2-Amino-4,6-O-Benzylidene-2,3-N,O-Carbonyl-2-Deoxy-2-N-(4-Methoxybenzyl)-1-Thio-β-d-Glucopyranoside (6) ................................. 117 Phenyl 2-Amino-4,6-O-Benzylidene-2,3-N,O-Carbonyl-2-Deoxy-2-N-(Prop-2-Enyl)-1-Thio-β-d-Glucopyranoside (7) .......................................... 118
N-2,2,2-Trichloroethoxycarbonyl (Troc)-protected glycosamine derivatives are versatile glycosyl donors in oligosaccharide syntheses. The Troc protecting group can easily be introduced via its acid chloride; it is stable under acidic conditions but is base labile. It can be selectively cleaved under reductive conditions. As a protecting group for the amino function in glycosamine donors, Troc behaves like a neighbor group active protecting group leading, upon Koenigs-Knorr type glycosylation,1-5 predominately to the corresponding 1,2-cis glycosides.
