A convenient synthesis of isotopically labelled anthraquinones, chrysophanol, islandicin, and emodin. Incorporation of [methyl-2H3]chrysophanol into tajixanthone in Aspergillus variecolor

Abstract

Cycloaddition reactions of labelled 6-methoxy-3-methyl-2-pyrone (1) with naphthoquinones provide the common fungal anthraquinones, chrysophanol (2), islandicin (3), and emodin (4) suitably labelled for biosynthetic studies, as demonstrated by synthesis and incorporation of [methyl-²H₃]chrysophanol into the xanthone metabolite, tajixanthone (17) in Aspergillus variecolor.