Total Synthesis of Waltherione F, a Nonrutaceous 3-Methoxy-4-quinolone, Isolated from Waltheria indica L. F.

Abstract

Waltherione F was totally synthesized in seven steps and 31% overall yield from 2-nitro-3-methylanisole without the use of protecting groups. Key steps in the sequence were a Suzuki-Miyaura coupling to attach the n-octyl chain and a microwave-promoted cyclization of an acetonyl anthranilate to give the heterocyclic core whose 3-OH was O-methylated.