CONFORMATIONAL STUDIES OF 3-HYDROXY-ALPHA-DAMASCONE BY NUCLEAR OVERHAUSER EFFECT NUCLEAR-MAGNETIC-RESONANCE EXPERIMENTS

A series of NOE experiments was carried out to clarify the conformation of cis- (1) and trans-3-hydroxy-alpha-damascone (2). For 1, half-chair conformation with a quasiequatorial hydroxy group and a quasiaxial side chain was determined. A main half-chair conformation with quasiequatorial positions both for the hydroxy group and for the side chain was also found for 2. According to the NOE experiments, an additional boat conformation with an equatorial hydroxy group and an axial side chain was postulated for 2.