NMR and Mass Spectra of Conformational Isomers of 2‐Methylpentane‐2,4‐Diol Sulfite

From the ester exchange reaction between 2‐methylpentane‐2.4‐diol and dimethyl sulfite, two isomeric cyclic sulfites were isolated in a 3 to 2 ratio. On the basis of IR and NMR data it was concluded that the isomers exist in the rigid chair conformation and the isomerism springs from the pyramidal SO orientation. An axial SO is assigned to the liquid isomer (predominant) and an equatorial SO to the solid compound (minor). The 25 ev mass spectra of the two isomers at room temperature is herein described.