NMR spectra and stereochemistry of 1,5- and 1,6-disubstituted perhydrooxazolo[3,4-a] pyridines
作者:Trevor A. Crabb、Andrew N. Trethewey
DOI:10.1002/mrc.1260270320
日期:1989.3
13C and 1H NMR spectroscopy showed that with the exception of r-1,t-6,t-8a-1-alkyl-6-ethylperhydrooxazolo[3,4-a] pyridines (alkyl = ethyl, isopropyl) which adopt the O-inside cis-fused conformation, all the other 1 -alkyl-6-ethyl- and 1-alkyl-cis(H-5, H - 8a) -5- methyl - perhydrooxazolo [3,4-a] pyridines adopt trans-fused conformations (CDCI3, 298 K).
13C和1H NMR光谱显示,除了r-1,t-6,t-8a-1-烷基-6-乙基-全氢氧唑并[3,4-a]吡啶(烷基=乙基、异丙基)采用O-内侧顺式融合构象外,其他所有1-烷基-6-乙基-和1-烷基-顺式(H-5,H-8a)-5-甲基-全氢氧唑并[3,4-a]吡啶均采用反式融合构象(CDCI3,298 K)。