A STRAIGHTFORWARD SYNTHESIS OF (PLUS-OR-MINUS)-4-AMINO-4-DEOXYERYTHROSE VIA ITS BISULFITE ANOMER

Hetero-Diels-Alder reaction of N-butadienyl-2-pyrrolidone (1a) with acylnitroso dienophile (3) led with very high regioselectivity to the racemic cycloadduct (6). A sequence of stereospecific reactions, as well as some protection/deprotection steps, gave the bisulfite derivative (2b) of (+/-)-4-amino-4-deoxyerythrose (2a) as a single and crystalline anomer. Asymmetric induction as applied to the Diels-Alder cycloaddition step with various N-butadienylpyroglutamate esters (1b-e) permitted to work out optimal experimental conditions, the best d.e. value being 76%.