Processo para a preparação de derivados 9-deoxo-8a-aza(8a-alquil)-8a-homoeritromicina a a partir da 9-deoxo-9(z)hidroxiiminoeritromicina a

摘要

The invention concerns a method for preparing 9-deoxo-8a-aza-(8a-alkyl)-8a-homoerythromycin A and its 8a-alkyl derivatives from 9-deoxo-9(Z)-hydroxyiminoerythromycin A via a Beckmann stereospecific rearrangement in a reaction medium using pyridine as main solvent, leading to imidate intermediates which are not isolated from said medium and which are directly engaged in a reduction step using a sufficient amount of borohydride, after extracting the pyridine with a hydrocarbon miscible therewith and wherein said imidates are insoluble. The compound (V) can be directly N-alkylated in position-8a, using an aldehyde, without being isolated from the reduction medium.