UNSATURATED SULFINAMIDES .8. STEREOCHEMICAL COURSE OF THE [2,3]-SIGMATROPIC REARRANGEMENT OF SUBSTITUTED PROPARGYL N,N-DIALKYLAMIDOSULFOXYLATES - X-RAY MOLECULAR-STRUCTURE OF [S(STAR),(S)R(STAR)]-4-[(1,4,4-TRIMETHYL-1,2-PENTADIENYL)SULFINYL]-MORPHOLINE

By the reaction with three N,N-dialkylamidosulfenyl chlorides 2 bearing representative sizes for the R group on the nitrogen atom, several substituted secondary propargylic alcohols (1a-f) have been converted into the corresponding pairs of diastereoisomeric allenic sulfinanides 3a-n and 3'a-j,l,m. Their ratios have been determined by H-1 NMR spectroscopy and were found to depend essentially on the sizes of both the R-1 and R groups of the starting materials. The stereochemistry of one pure diastereoisomer 3m has been determined by a single crystal X-ray analysis. When treated with p.toluenesulfenyl chloride, the alcohol if led to a major alpha-allenic sulfoxide 5 which was found to be identical to that prepared by unambiguous procedures from the major alpha-allenic sulfinamide 3m.