Substituted tetralins VI: Tentative assignment of absolute stereochemistry of 1-methyl-1-phenyl-1,2,3,4-tetrahydro-3-naphthoic acid and N,N,1-trimethyl-1-phenyl-1,2,3,4-tetrahydro-3-naphthylamine isomers.

The absolute configurations of the enantiomers of N,N,1-trimethyl-cis- and trans-1-phenyl-1,2,3,4-tetrahydro-3-naphthylamines (Ia and Ib) were assigned tentatively from the circular dichroism spectrum of a bridged ketone derived by cyclization of optically active 1-methyl-cis-1-phenyl-1,2,3,4-tetrahydro-3-naphthoic acid (IIa). Thus, (--)-IIa and the corresponding amine, (--)-Ia, were assigned the (2S, 4R)-configuration. Epimerization of (--)-IIa through its methyl ester yielded the trans-acid, (--)-IIb, which established the absolute configuration of (--)-IIb and the corresponding amine, (--)-Ib, as (2R, 4R).