Facile syntheses of 4-hydroxy-7-methyl-1-indanone, isolated from cyanobacterium Nostoc commune

Abstract

Two different high yielding synthetic routes both starting with 6-methylcoumarin 2 have been described to prepare 4-hydroxy-7-methyl-1-indanone 1, a constituent of cyanobacterium Nostoc commune having antibacterial activity. In the first route, methylative lactone ring opening of the coumarin 2 followed by catalytic hydrogenation of the cinnamyl double bond and subsequent PPA cyclization gives the methyl ether 5 of 1 which on demethylation gives 1 in excellent yield. Alternatively, catalytic hydrogenation of 2 followed by fusion with anhydrous AlCl(3) gives high yield of 1 just two steps.