α-Hydroxyphosphonates as versatile starting materials

alpha-Hydroxyphosphonates constitute a class of organophosphorus compounds famous for their bioactive properties. alpha-Hydroxyphosphonates may easily be functionalized due to their free hydroxy function in the alpha position resulting in new families of compounds of synthetical and biological interest. This review paper summarizes the main reaction types of alpha-hydroxyphosphonates. First, the syntheses of alpha-aminophosphonates and alpha-hydroxyphosphonic acids are discussed, as from a biological point of view, these are the most important classes of compounds derived from alpha-hydroxyphosphonates. After that, the O-acylation and O-alkylation of alpha-hydroxyphosphonates to afford O-acyloxy and O-alkoxyphosphonates are presented. The discussion continues with the synthesis of alpha-halophosphonates and alpha-ketophosphonates that are valuable synthetic intermediates. After that, a few examples for the reduction of alpha-hydroxyphosphonates are presented, followed by the rearrangement of alpha-hydroxyphosphonates to the corresponding benzyl phosphates. Beside the interesting examples from the literature, the main synthetic results of our research group in this field are also discussed. [GRAPHICS] .