The absolute configuration of (+)-2-benzyl-2-[N-(α-phenylethyl)amino]cyclohexanone hydrochloride

Abstract

C 21 H 25 NO.HCl, M r =343.90, orthorhombic, P2 1 2 1 2 1 , a=8.588 (1), b=11.700 (1), c=18.130 (2) A, V=1821.7 (4) A 3 , Z=4, D x =1.254 Mg m -3 , λ(Mo Kα)=0.71069 A, μ=2.139 mm -1 , F(000)=736, T=293 K, final R=0.037 for 3192 observed reflections. Condensation of 2-(benzyloxy)cyclohexanone with (R)-1-phenylethylamine yields, by rearrangement, an unexpected reaction product mixture of (αR,2S)- and (αR,2R)-2-benzyl-2-[N-(α-phenylethyl)amino]cyclohexanone hydrochlorides. The absolute configuration of one the epimers (the title compound) is elucidated as (αR, 2S), showing the cyclohexanone ring in the chair conformation