Reactions of ketene acetals. 10. Total syntheses of the anthraquinones rubrocomatulin pentamethyl ether, 2-acetylemodin, 2-acetyl-5-hydroxyemodin tetramethyl ether, and xanthorin
Reactions of ketene acetals. 10. Total syntheses of the anthraquinones rubrocomatulin pentamethyl ether, 2-acetylemodin, 2-acetyl-5-hydroxyemodin tetramethyl ether, and xanthorin