摘要
The conformations ofγ-butyrolactone ring in solution were deduced on the basis of ~1H NMR spectra of geminal protons of the butyrolactone ring.A series of optically pure(Z)-(-)-4-(1 -alkoxyl-1 -carbalkoxy-methylene)-5(R)[(1R)-menthyloxy]-γ-butyr-olactones with a stable planar conformation of γ-butyrolactone ring were found.
The conformations ofγ-butyrolactone ring in solution were deduced on the basis of ~1H NMR spectra of geminal protons of the butyrolactone ring.A series of optically pure(Z)-(-)-4-(1 -alkoxyl-1 -carbalkoxy-methylene)-5(R)[(1R)-menthyloxy]-γ-butyr-olactones with a stable planar conformation of γ-butyrolactone ring were found.
