Ebenaceae extractives. Part 10. Macassaric acid, an o-methoxycarbonylcinnamic acid from macassar ebony
Abstract
Macassaric acid is shown to be the cis-cinnamic acid derivative (3). The corresponding methyl ester (4) is synthesised from the o-naphthoquinone (9)via the cyclic unsaturated anhydride (8). Related reactions give the isochromenone (10), the methoxy anhydride (13), and the trans-cinnamic acid (15) and its methyl ester. Macassaric acid appears to be a catabolic product of macassar II (1).