SYNTHESIS OF ANTITUMOR LYCORINES BY INTRAMOLECULAR DIELS-ALDER REACTION

摘要

Pharmacologically interesting lycorines were obtained by a short, efficient method based on an intramolecular Diels-Alder reaction between an alpha-pyrone and an alkyne, followed by loss of CO2 in a retro Diels-Alder reaction. The cyclization precursors (pyrones 9) were obtained in good yields in two or three steps from the corresponding homophthalic acid or anhydride. [References: 33]