Novel ethynylcerium(III) reagents as efficient tools for constructing the .ALPHA.-hydroxy methyl ketone moiety of anthracyclinones.
作者:MICHIYO SUZUKI、YOSHIKAZU KIMURA、SHIRO TERASHIMA
DOI:10.1248/cpb.34.1531
日期:——
The title cerium(III) reagents (7-10) were found to react with 5, 8-dimethoxy-2-tetralone (11a) and 5, 12-dihydroxy-1, 2, 3, 4-tetrahydronaphthacene-2, 6, 11-trione (15) more efficiently than the corresponding lithium and magnesium reagents (3, 5, and 4, 6), giving the addition products (12a, 13a, and 17) in high yields. Hydration of these adducts readily afforded the α-hydroxy methyl ketones, 2-acetyl-5, 8-dimethoxy-1, 2, 3, 4-tetrahydro-2-naphthol (14a), and 2-acetyl-2, 5, 12-trihydroxy-1, 2, 3, 4-tetrahydronaphthacene-6, 11-dione (4-demethoxy-7-deoxydaunomycinone) (18), which are versatile synthetic intermediates for optically active 4-demethoxyanthracyclinones.
标题铈(III)试剂(7-10)被发现与5, 8-二甲氧基-2-四氢萘酮(11a)和5, 12-二羟基-1, 2, 3, 4-四氢萘蒽-2, 6, 11-三酮(15)反应更有效,相比于相应的锂和镁试剂(3, 5, 和 4, 6),生成加成产物(12a, 13a, 和 17),产率较高。这些加成物的亲水化迅速提供了α-羟甲基酮,2-乙酰基-5, 8-二甲氧基-1, 2, 3, 4-四氢-2-萘酚(14a),和2-乙酰基-2, 5, 12-三羟基-1, 2, 3, 4-四氢萘蒽-6, 11-二酮(4-去甲氧基-7-脱氧道诺霉酮)(18),它们是光学活性4-去甲氧基蒽环酮的有用合成中间体。