Reaction of trans-2-Acylaminocyclanols with Thionyl Chloride

trans-2-Acetamidocyclohexanol ( 1 ; n = 2, R = CH 3 ) on addition to thionyl chloride in chloroform at 0° was converted rapidly and quantitatively to D,L -2-methyl-4,5-cis-cyclohexanoöxazoline hydrochloride ( 2 ; n = 2, R = CH 3 ) judging from shifts in the methyl proton resonances of the n.m.r. spectra of the amide and the reaction solution. The intermediate chlorosulfinate was estimated to have a half-life of less than 2.25 min. The oxazoline salt was isolated in 98% yield by sublimation of the crude product in vacuo and was identified by its i.r. and n.m.r. spectra and by its facile and almost quantitative hydrolysis to cis-2-aminocyclohexanol hydrochloride. The oxazoline salts 2 (n = 1, R = CH 3 , and n = 2, R = C 6 H 5 , ) were readily obtained in 95 % yield or better by the same general method and it was shown that the trans-2-acetamidocyclanols are the preferred starting materials for conversion to cis-2-aminocyclanol derivatives by the thionyl chloride inversion reaction. The oxazoline bases 4 (n = 1, R = CH 3 , and n = 2, R = CH 3 , ) were readily obtained in high yield from the corresponding salts and differences in the i.r. and n.m.r. spectral characteristics of the salts and bases are reported.