1997 Volume 55 Issue 10 Pages 897-906
The first isolable, unoxidized dithiirane, 3-phenyl-3- (1, 1, 3, 3-tetramethyl-4-oxo-4-phenylbutyl) dithiirane (16) was prepared by treatment of 2, 2, 4, 4-tetramethyl-1, 5-diphenyl-6, 7-dithiabicyclo- [3.1.1] heptane (14) with 2 KHSO5·KHSO4·K2SO4 (OXONE®) or NaOCl-NaClO4. Monooxides of 14 gave the corresponding dithiirane 1-oxides 17 and 18 by reaction with OXONE®. Under similar conditions, some other dithiirane derivatives were obtained from 5, 6-dithiabicyclo [2.1.1] hexanes, 6, 7-dithiabicyclo [3. 1. 1] heptanes, and 7, 8-dithiabicyclo [4. 1. 1] octanes.
It was disclosed by a study on competitive thermal reactions that a 3, 3-di-tert-alkyldithiirane is thermodynamically less stable but kinetically more stable than 3-alkyl-3-aryldithiirane 16.
(1RS, 3SR) - and (1RS, 3RS) -Dithiirane 1-oxides, 17 and 18, respectively, were optically resolved by HPLC equipped with a chiral column and absolute configurations of the four stereoisomers were determined by X-ray single-crystal structure analysis and a chemical property. The mechanism of the racemization (1, 2-oxygen migration) between the respective enantiomers were also discussed.
