A convergent AB + CD route to daunomycinone (1) is described. The AB segment is synthesized from the Diels–Alder adduct (3) of an isobenzofuran and methyl vinyl ketone by means of an unusual 5-endo–trig cleavage (3 → 4). The CD half (9) is combined with the AB by the Kraus annelation technique to provide a 9-deoxy daunomycinone derivative (12a) which is subsequently oxygenated.
本文介绍了一种收敛的AB + CD途径合成多柔比星酮(1)的方法。AB段是通过异苯并呋喃和甲基乙烯酮的Diels-Alder加合物(3)进行非常规的5-内端反应裂解(3→4)合成的。CD半部分(9)通过Kraus环化技术与AB结合,提供了一个9-去氧多柔比星酮衍生物(12a),随后进行氧化反应。