Reactions of Lactonic Compounds with Nitrogen-containing Reagents. II. Reaction of Meranzin with Dimethylamine or Piperidine

Synthetic meranzin (IVa) was treated with dimethylamine or piperidine in methanol at 40-42°(condition A) and in benzene at 150°(condition B). cis-Amides (VII) and (IX) and trans-amides (VIII) and (X) were obtained under conditions A and B, respectively. Re-examination of the reaction of natural IVa with dimethylamine under condition B revealed that the product was not V proposed by Bohme, et al. but one of the optical isomers of VIII. Treatment of natural IVa with dimethylamine under condition A gave one of the optical isomers of racemic VII. VII-VIII or IX-X equilibrium in ethanol induced by diffused light was also described.