Asymmetric hetero-Diels–Alder reactions. Reactions of oxazolo[3,2-c]pyrimidines

Diastereomerically pure oxazolo[3,2-c]pyrimidines can be readily prepared by the reaction of alkenyloxazolines with isocyanates. The mechanism of this transformation has been investigated computationally. These compounds undergo epimerisation upon prolonged heating, a reaction which is consistent with the proposed stepwise mechanism. Hydrolysis reactions of these compounds have been investigated.