Asymmetric synthesis of optically pure tert-butyl sulfoxides using the 'DAG methodology'

Diacetone- D -glucose (DAG) reacts with t -BuSOCl in the presence of NEt 3 and Py to give (−)-( S )- and (+)-( R )- tert -butanesulfinate respectively, in high diastereomeric excess. These sulfinates were transformed into various enantiomerically pure tert -butyl sulfoxides by reaction with different Grignard reagents. Additionally, the reaction of tert-butylmagnesium chloride with (+)-( R )- and (−)-( S )-methanesulfinates of DAG has been found to occur with complete inversion of configuration and not with retention as previously reported.