Spectroscopic study of 3‐methyl‐2,4‐diphenyl‐3‐azabicyclo[3.3.1]nonan‐9‐α(β)‐ols

Abstract

3‐Methyl‐2,4‐diphenyl‐3‐azabicyclo[3.3.1]nonan‐9‐α(β)‐ols have been synthesized and studied by ir, 1H and 13C nmr spectroscopy. In deuteriochloroform and perdeuteriobenzene solutions, these compounds adopt a flattened chair‐chair conformation in which the cyclohexane ring is more flattened. From the 1H and 13C nmr data, several stereoelectronic effects have been deduced. The complete and unambiguous assignment of all protons of the 3‐azabicyclo[3.3.1]nonane system, not described up to date, has been carried out.

Synthesis, structural, conformational and pharmacological study of esters derived from 3‐methyl‐2,4‐diphenyl‐3‐azabicyclo[3.3.1]nonan‐9α‐ol as potential analgesics

“…3 Owing to the small differences in the chemical shifts of the H7 ax and H2(4) ax between the alcohol (1) and esters (2-5), we can conclude that the position adopted by the phenyl groups in 2-5 will be the same as that found in the alcohol 1, 3 with near coplanarity with respect to H2(4) ax , as was observed in the x-ray structure of 2.…”

“…Assignments of proton and carbon resonances were made on the basis of the literature data for 3-methyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9a-ol 3 and related systems. 14 …”

“…We report here the synthesis and structural analysis, based on 1 H and 13 C NMR spectroscopy, of a series of esters derived from 3-methyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9a-ol (2)(3)(4)(5). In order to determine their preferred conformation both in solution and in the solid state, the crystal structure of 2 was determined.…”

Chemistry of 3-Azabicyclo[3.3.1]nonane: II. Reduction of 6-Acetoxy-3-benzyl-1- ethoxycarbonyl-3-azabicyclo[3.3.1]nonan-9-one with Sodium Borohydride

“…The assignment of signals belonging to alcohols α α α α α,β β β β β-(IIIa, IIIf) was performed, firstly, by the intensity of the signals from the mentioned groups (isomer ratio 1:12), and secondly, by comparison with the signals of the initial acetate IIa, f and with those of diol α α α α α,β β β β β-(IVf) isolated in an individual state. According to calculated [7] and also published data [3,8,9] the upfield signal of C 9 atom, δ 77.20 ppm, corresponds to the α-epimer, and the downfield signal, δ 68.54 ppm, to the β-epimer of the prevailing isomer IIIf whereas the signals at δ 73.22 (α α α α α) and 71.37 (β β β β β) ppm respectively belong to the minor isomer IIIa.…”