Andrzej Robert Daniewski

A CONVENIENT SYNTHESIS OF R-(-)-CARNITINE FROM R-(-)-EPICHLOROHYDRIN

Abstract A convenient four-step synthesis of R -(−)-carnitine ( 1 ) is described from the reaction of R -(−)-epichlorohydrin ( 2 ) with vinylmagnesium bromide followed by formation of the ammonium salt 4 with trimethylamine and finally ozonolysis of the corresponding ammonium hydroxide 5 .

Improved preparation of A-ring phosphine oxides for the synthesis of vitamin D analogs

ABSTRACT A new, high yielding, two-step process for the preparation of A-ring phospine oxides from allyl alcohols, useful for the synthesis of vitamin D analog, is described, in which triphosgene and diphenylphosphine oxide are used for chlorination and subsequent substitution reactions, respectively.