Transformations of 3-(methylene)dihydro-2(3H)-furanone derivatives

(E) and (Z)-3-(4-toluenesulfonyloxymethylene)dihydro-2(3H)-furanones ((E)-I) and ((Z-I) react with piperidine, pyrrolidine, morpholine, butanethiol, 4-toluenethiol, and 2-naphthalenethiol to give (E)-isomers of the corresponding enamines II-IV and thiomethylene derivatives V-VII in high yields. As has been shown, the reactions proceed with retention of configuration; the initially formed (Z)-II, (Z)-III, (Z)-IV, and (Z)-V isomerize rapidly to the thermodynamicaly more stable (E)-isomers. Ether IX was obtained by reaction of (E)-I with the (E)-isomer of sodium salt of 3-(hydroxymethylene)dihydro-2(3H)-furanone ((E)-VIII) and a mixture of ethers IX and X resulted from reaction of (Z)-I with sodium salt of (E)-VIII. Compounds (E)-I and (Z)-I afforded the corresponding azides(E)-XI and (Z)-XI upon treatment with sodium azide, and hydroxybutanoic acids (E)-XII and (Z)-XII with sodium hydroxide in aqueous acetone. Chloride (E)-XIII, prepared by reacting (E)-I with methanolic hydrogen chloride, furnished with piperdine, pyrrolidine, morpholine, or 2-naphthalenethiol the corresponding (E)-II, (E)-III, (E)-IV, and (E)-VII. Potassium cyanide reacted with (E)-I in dimethylsulfoxide to yield nitrile (E)-XIV. Cycloaddition of the azide (E)-XI to isobutyl vinyl ether or cyclohexyl vinyl ether proceeds quantitatively to give the respective triazolines (E)-XV and (E)-XVI. Alkaline hydrolysis of IX afforded the acid XVII. reduction of (E)-I, (Z)-I, and (E)-VII with chloralane gave the respective butanediols (E)-XVIII, (Z)-XVIII, and (E)-XIX, respectively. Configurations of these substances were elucidated by 1H NMR spectrometry.