Semi-syntheses of the 11-hydroxyrotenoids sumatrol and villosinol†
David A. Russell,Julien J. Freudenreich,Hannah L. Stewart,Andrew D. Bond,Hannah F. Sore,David R. Spring
Organic & Biomolecular Chemistry Pub Date : 08/22/2018 00:00:00 , DOI:10.1039/C8OB01919C
Abstract

We describe semi-syntheses of the 11-hydroxyrotenoids sumatrol (1) and villosinol (2), starting from rotenone (5), using an oxime-directed C11–H functionalisation approach. Thus, rotenone (5) was converted into rotenone oxime (6), which gave dimeric palladacycle 7 following reaction with Na2PdCl4·3H2O. Controlled, divergent, oxidation of palladacycle 7 with either Pb(OAc)4 or K2Cr2O7 afforded the 11-acetoxylated intermediates 9 and 13, respectively, which were transformed into sumatrol (1) and villosinol (2).

Graphical abstract: Semi-syntheses of the 11-hydroxyrotenoids sumatrol and villosinol