Abstract
Differentially protected 4-azido- or 4-amino-3-hydroxy-l-prolines were synthesized in good overall yields (21–31%) from d-glucose. The synthetic strategy involved conversion of d-glucose into 3-[(benzyloxycarbonyl)amino]-3-deoxy-1,2-O-isopropylidene-α-d-glucofuranose, which was subjected to mesylation of the 5- and 6-hydroxy groups and
subsequent intramolecular SN2 displacement of the 6-O-mesyl group by the 3-(benzyloxycarbonyl)amino group to give a pyrrolidine ring. The
resulting intermediate underwent intermolecular SN2 displacement of the 5-O-mesyl group with sodium azide, hydrolysis of 1,2-acetonide group, treatment with
sodium periodate, and Pinnick oxidation to give the required compounds.
Key words
amino acids - chemoselectivity - carbohydrates - cyclization - pyrroles - stereoselective
synthesis
