Condensation of 2-p-toluoylcyclohexanecarboxylic acid (1a,b) with primary amines gave the corresponding hexahydroisoindol-1-ones (2a-g) in good yield. The octahydro derivatives (4a-g) were prepared from cis- and trans-hexahydro-1(2H)-phthalazinone (3a,b) by reduction with zinc-hydrochloric acid via ring contraction. Stereoselective synthesis of cis-N-phenyloctahydroisoindol-1-one (4h) was performed starting from 2b by reduction with magnesium-methanol at room temperature. Configurational assignments of cis and trans isomers were based on 1H-and 13C-nmr spectroscopic studies.
QC 20220915