Compounds with bridgehead nitrogen: 45—the1H NMR spectra and stereochemistry of some dimethylperhydro-oxazolo[3,4-a]pyridines
作者:Trevor A. Crabb、Geoffrey C. Heywood
DOI:10.1002/mrc.1270200411
日期:1982.12
AbstractThe positions of conformational equilibria in 1,5‐, 1‐6‐ and 1,8‐dimethylperhydro‐oxazolo[3,4‐a]pyridines were determined by 1H NMR spectroscopy. The cis‐(H‐5, H‐8a)‐1,6‐dimethyl‐perhydro‐oxazolo[3,4‐a]pyridine. In contrast, r‐1,t‐6,t‐8a‐1,6‐dimethylperhydro‐oxazolo[3,4‐ a]pyridine preferred the cis‐fused conformation. Three of the 1,8‐dimethylperhydro‐oxazolo[3,4‐a]pyridines adopted the trans‐fused conformations (with distortion of the system in the case of the r‐1,c‐8,c‐8a derivative) and the r‐1,c‐8,t‐8a‐1,8‐dimethyl derivative adopted the cis‐fused conformation.