A simple and efficient total synthesis of the sesquiterpenes cuparene and iso-α-curcumene, from furan derivatives

Abstract

3,3-Dimethyl-2-p-tolylcyclopentanone (7) was synthesised by 1,4-addition of lithium dimethylcuprate to 3-methyl-2-p-tolylcyclopentenone (6), which was derived from 5-methyl-2-(4-methylbenzyl)furan (4) through the diketone (5). Starting from the same intermediate (5), 2-p-tolylheptan-6-one (16) was also synthesised. These results constitute formal total syntheses of cuparene (9) and iso-α-curcumene (17) respectively.