Cyclofunctionalisation reactions of epoxyalcohol derivatives. 3. cyclisationacyl migration of n-benzoylcarbamates to stereodefined oxazolidinones. A new, diastereospecific route to thiamphenicol.
作者:S.W. McCombie、T.L. Nagabhushan
DOI:10.1016/s0040-4039(00)96737-6
日期:1987.1
N-Benzoylcarbamates formed from 2,3-epoxyalcohols and PhCONCO undergo clean N 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
由2,3-环氧醇和PhCONCO形成的N-苄基氨基甲酸酯经过干净的N-C-2环化,然后在用催化咪唑钠或其他碱处理时N-O酰基迁移。随后的苯甲酸酯裂解(NaOMe)伴随着N-未取代的恶唑烷酮的平衡; MeLi或Zn(BH4)2可实现无明显异构化的酶切。该方法适用于非对映异构的,6-甲基4-溴苯基砜向外消旋的甲砜霉素的6步转化。