CYCLOFUNCTIONALISATION REACTIONS OF EPOXYALCOHOL DERIVATIVES. 3. CYCLISATION-ACYL MIGRATION OF N-BENZOYLCARBAMATES TO STEREODEFINED OXAZOLIDINONES. A NEW, DIASTEREOSPECIFIC ROUTE TO THIAMPHENICOL.

Article abstract of DOI:10.1016/S0040-4039(00)96737-6

N-Benzoylcarbamates formed in situ from 2,3-epoxyalcohols and PhCONCO undergo clean to C-2 cyclisation followed by N to O acyl migration on treatment with catalytic sodium imidazolide or other bases.Subsequent benzoate cleavage (NaOMe) is accompanied by equilibration of the N-unsubstituted oxazolidinones; cleavage without significant isomerisation is achieved with MeLi or Zn(BH4)2.This methodology is applied in a diastereospecific, 6-step conversion of methyl 4-bromophenyl sulfonate to racemic Thiamphenicol.