Syntheses of Two Microbial Metabolites, 5-Chloro-3, 4-dihydro-8-hydroxy-6-methoxy-3-methylisocoumarin and 8-Hydroxy-6-methoxy-3-methylisocoumarin

Abstract

The racemate of 5-chloro-3, 4-dihydro-8-hydroxy-6-methoxy-3-methylisocoumarin (I), a fungal metabolite of Periconia macrospinosa, was synthesized from 6-chloro-3, 5-dimethoxyhomophthalic acid (III) via compounds IV, VI, VII and VIII. Catalytic hydrogenation of V resulted in dechlorination, yielding 6-methoxy-8-hydroxy3-methylisocoumarin (II), another natural product from Streptomyces mobaraensis.