REACTIVITY AND STEREOCHEMICAL STRUCTURE OF 4-HYDROXY- AND 4-ALKOXYHEXAHYDROPYRIMIDINE-2-THIONES

Article abstract of DOI:10.1007/BF00504213

Substituted 4-hydroxyhexahydropyrimidine-2-thiones were obtained by the reaction of β-isothiocyanatoaldehydes with ammonia or methylamine.When heated with alcohols in the presence of p-toluenesulfonic acid, the synthesized compounds gave the corresponding 4-alkoxyhexahydropyrimidine-2-thiones, which were converted into other 4-alkoxy derivatives by the action of the respective alcohols and were hydrolyzed to the initial 4-hydroxyhexahydropyrimidine-2-thiones by the action of an aqueous solution of oxalic acid or potassium hydroxide.The reaction of the4-hydroxyhexahydropyrimidine-2-thiones with methyl iodide led to the formation of 2-methylthio-4-hydroxy-3,4,5,6-tetrahydropyrimidine hydroiodides.It was shown by PMR spectroscopy that the stereoisomers in which the hydroxyl (or alkoxyl) group has the axial orientation are thermodynamically more stable.