Sugar-derived cyclic nitrones were synthesized from the corresponding aldoses through an efficient and practical procedure involving a seven-step reaction sequence in good to excellent overall yield (10-42%). This synthetic strategy, requiring only inexpensive reagents, is easy to perform and hence suitable for large-scale preparations.
A systematic study of diastereoselective nucleophilic addition of Grignard reagents to six-membered chiral tri-O-benzyl cyclicnitrones is described. With all eight chiral cyclicnitrones and asymmetric reaction conditions in hand, a practical methodology is established for the preparation of diverse 1-deoxyazapyranosides bearing various stereogenic centers.