Synthesis,structural and conformational study of some esters derived from 8-phenethyl-8-azabicyclo[4.3.1]decan-10α-ol

A series of 10α-acyloxy-N-phenethyl-8-azabicyclo4.3.1]decane derivatives have been synthesized and studied by ¹H and ¹³C nmr spectroscopy, and the crystal structure of N-phenethyl-10aL-(xanten-9″-carbonyloxy)bicyclo4.3.1]decane 2 has been determined by X-ray diffraction. The compounds studied display in deuteriochloroform the same preferred conformation adopted by the piperidine ring as a distorted chair conformation flattened at N-8 with both the phenethyl and acyloxy groups in the equatorial position with respect to the piperidine ring. These results are in close agreement with that found for compound 2 in the crystalline state.