tetrahydropyrone's structure is very similar to that of benzene. Modern physical methods show that the length of carbon-carbon bonds in tetrahydropyrone molecule is 139pm, which lies between C-N single bonds (147pm) and C=N double bonds (128pm), and the values of the length of carbon-carbon bonds and carbon-nitrogen bonds are similar. The bond Angle is about 120 degrees, which means that the...