申请人:Rhone-Poulenc Nutrition Animale
公开号:US05145972A1
公开(公告)日:1992-09-08
The present invention relates to a process for preparing halo acetals of ethylenic aldehydes by reaction of a halogen cation with enamine followed by a hydrolysis and reaction with an alcohol, a glycol or an orthoformate. These halo acetals are used as intermediate for the synthesis of vitamins A and E. It also relates to a new compound of formula (IV), ##STR1## to a process for preparing it from halo acetals of ethylenic aldehydes by reaction with triethyl phosphate, and to its use for the preparation of retinal by reaction with .beta.-ionylideneacetaldehyde.
本发明涉及一种制备乙烯醛卤代缩醛的方法,通过卤素阳离子与恩酰反应,随后水解并与醇、二元醇或正酯反应。这些卤代缩醛用作合成维生素A和E的中间体。它还涉及一种新的化合物,化学式为(IV),##STR1##,通过与三乙酰磷反应从乙烯醛卤代缩醛制备它的方法,以及它用于通过与β-离甲醛反应制备视黄醛的用途。