Carbohydrate-Derived Dienes for Intramolecular and Asymmetric Diels-Alder Reactions.

3-Acyloxydienes 2 and 10, derived from tri-O-acetyl-D-glucal are converted into appropriate substrates to perform intramolecular Diels–Alder reactions, thus yielding cis- or trans-fused bicyclic compounds. Attempts are made to rationalize the observed ratios between cycloadducts, as well as those previously reported in the literature for related experiments, by theoretical studies at the PM3 semiempirical level. In addition, the new chiral diene 9 derived from D-galactose or D-mannose, via an aldehydo-heptose, is obtained; the Diels–Alder reaction of 9 with N-phenylmaleimide is studied, and the observed asymmetric induction is explained by PM3 and B3LYP/6-31G* calculations.