EFFICIENT SYNTHESIS OF 4-SUBSTITUTED 4,5-DIHYDROISOXAZOL-3-OLS FROM MORITA-BAYLIS-HILLMAN BROMIDES

摘要

An efficient synthesis of 4-substituted 4,5-dihydroisoxazol-3-ols was achieved with high regioselectivities and satisfactory yields via addition of N-hydroxyphthalimide to Morita-Baylis-Hillman (MBH) bromides with ester moiety, followed by hydrazinolysis and intramolecular cyclization. Surprised, the unexpected isoxazolidine-4-carbonitrile was obtained when using MBH bromide with nitrile moiety as substrate under the similar conditions.