STRUCTURES OF 2 DIASTEREOISOMERIC SULFOXIDES . 3,5-DIHYDRO-3-METHYL-4,1-BENZOTHIAZEPIN-2(1H)-ONE 4-OXIDES

The sodium metaperiodate oxidation of 3,5-dihydro-3-methyl-4, 1-benzothiazepin-2(1H)-one gave two diastereoisomeric sulfoxides with mp 220-223 and 246-248°, respectively. The crystal structure of the major product (mp 220-223°) has been determined and the 3-methyl group has been shown to be trans to the sulfoxide oxygen atom. The crystals are monoclinic, with a = 13.20 ± 0.02 Å, b = 4.71 ± 0.01 Å, c = 17.16 ± 0.03 Å and β = 113° 15′ ± 15′. There are four molecules of C10H11NO2S in the space group P21/c. The st ructure has been refined to an R factor of 0,09 on 1427 reflections, obtained photographically. The detailed geometry of the molecule in the crystal is described. In boiling acetic anhydride solution both sulfoxides interconvert and rearrange to 3-acetoxy-3,5-dihydro-3-methyl-4,1-benzothiazepin-2(1H)-one. © 1969, American Chemical Society. All rights reserved.