1-Indancarboxylic acids. IV. A convenient synthesis of antiinflammatory 4-aroyl-1-indancarboxylic acids and their absolute configurations.

Antiinflammatory 4-aroyl-1-indancarboxylic acids (I) were synthesized from the corresponding 4-aroyl-1-indanones (XI) by the one-carbon homologation reaction using p-toluenesulfonylmethylisocyanide (TosMIC, II) via 4-aroyl-1-indancarbonitriles (XIV). Among them, three compounds (Ia, b and c) were resolved into their enantiomers and it was found that the antiinflammatory activity virtually resides in the levo isomers, the absolute configurations of which were assigned the sinister series by the optical rotatory dispersion spectra.