Crystalline 5-O-acetyl-2,3-isopropylidenedioxy-d-ribonolactone oxime (8) was synthesised from d-ribose in 40% overall yield. The chloronitroso dienophile 3b was obtained from 8 by oxidation with t-BuOCl and underwent asymmetric Diels-Alder reaction with cyclic and acyclic dienes 10-13 to give crystalline adducts 14a-17a in good yield and excellent enantiomeric excess (93-99%).