Regiospecific synthesis of mono- and bicyclic 6-alkoxy-2-pyrones and their use in the preparation of substituted aromatics, anthraquinones, and tetracyclic intermediates for 11-deoxyanthracycline synthesis
作者:Michael E. Jung、John A. Lowe、Mark A. Lyster、Manabu Node、Rudolf W. Pfluger、Richard W. Brown
DOI:10.1016/s0040-4020(01)91537-6
日期:1984.1
chrysophanol, helminthosporin, pachybasin, 2-acetylemodin and the purported structure for orientalone. The utility of this approach for the synthesis of the anthracyclines is demonstrated by its use in the preparation of various tetracyclicintermediates for anthracycline synthesis.
(4a) derived from bis(trimethylsilyl) allenedicarboxylate (3) and furan, followed by treatment of the products (5) and (8) with diazomethane, afforded the corresponding αβ-unsaturated methyl esters (6) and (9) respectively. Catalytic hydrogenation of both compounds provided the desired methyl esters (7) and (10) which were identical to the compounds derived by Arndt–Eistert reaction of the halogenolactonic