短刺虎刺素的结构更正及其合成

短刺虎刺素的结构文献曾报道为1-甲氧基-2-羟基-3-乙氧甲基蒽醌(1)⁽²⁾。作者以邻苯二甲酸酐和2,3-二羟基甲苯或2.6-二羟基甲苯经环合、选择性乙酰化、甲基化、溴化、乙醇钠缩合分别合成了1和1-甲氧基-2-乙氧甲基-3-羟基蒽醌(5)。经对照后证实,短刺虎刺素的结构应更正为5,即虎刺素-ω-乙基醚。

STRUCTURE CORRECTION AND SYNTHESIS OF SUBSPINOSIN

"Subspinosin" isolated from the root of Damnacanthus subspinosus Hand-Mazz (Rubiaceae) and deduced as 3-ethoxymethyl-2-hydroxy-1-methoxyan-thraquinone 1 by Li et al in 1981, should be corrected as 2-ethoxymethyl-3-hydroxy-1-methoxyanthraquinone 5 by comparison with the synthetic compound. Since 5 is already known as damnacanthol-omega-ethyl ether, the name "Subspinosin" for 1 (not yet a natural isolate) should be abandoned in order to acknowledge this priority, and, what is more, to avoid confusion. The anthraquinones 1 and 5 were synthesized by condensation of phthalic anhydride with 3-methylcatechol or 2-methylresorcinol in fused AlCl3/NaCl (5:1), followed sequentially by selective acetylation, methylation, bromination and condensation with sodium ethoxide.