Three-dimensional structures of 2-alkyl-4-formyltetrahydropyrans

The three-dimensional structures of a number of diastereomeric 2-alkyl-4-formyltetrahydropyrans were studied by means of ¹H and ¹³C NMR spectroscopy. It is shown that the 2,2-dialkyl derivatives are mixtures of two configurational isomers in which the formyl group is equatorially oriented. 2-Monoalkyl-4-formyltetrahydropyrans exist in the form of mixtures of two diastereomeric forms that have different orientations (axial and equatorial) of the formyl group; the alkyl group in both isomers is equatorially oriented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 311–314, March, 1979.