Hydroxyalkylphosphonic diesters

It has been shown that the rearrangement of a-hydroxyalkylphosphonic acid diesters to phosphates is subject to general base catalysis and a transition state similar to (95) was proposed. Hydrolysis of the aroyl-phosphonate esters (96) in aqueous dioxan with phosphate buffer is also... 

In Section VILA, the 1,2-addition of a hydrogenphosphonic diester or related compound to an a,j5-unsaturated aldehyde or analogous ketone " " was discussed in relation to the synthesis of (l-hydroxyalkyl)phosphonic diesters. The latter are formed under condition of kinetic control whereas 1,4-addition (the so-called Pudovik reaction), which leads to the (2-oxoalkyl)phosphonic diester occur under thermodynamic controP" ". In general, reactions which involve ethylenic aldehydes, or acetylenic aldehydes or ketones, tend to result in adduct formation across the carbonyl group, whilst ethylenic ketones tend to take part in 1,4-additions and afford 3-oxoalkyl phosphonic (or phosphinic) acid systems 550 34,946-949 consistent with Markovnikov predictions. Such statements are a broad oversimplification, however, at least with regard to the formation of the oxoalkyl phosphonates. In practice, the manner of addition depends on experimental circumstances, the nature and even amount of catalyst and other factors For instance, for the additions of dimethyl hydrogenphosphonate to the ketones 561 ( = 1 or 2) and 559 (R" = H, R = 2-furyl, R = Me), carried out by the addition of a trace of saturated MeONa-MeOH solution to a mixture of reactants in diethyl ether, yielded (within 5 min) the respective 1,2-adducts (1-hydroxyalkylphosphonates) in yields of64,69 and 52% ... 

Dialkyl alkylene diphosphonates obtained by transesterification of dialkyl H-phosphonates with diols in the excess of H-phosphonate diesters are bifunctional monomers possessing two reactive P-H groups. The addition of ketones or aldehydes to dialkyl alkylene diphosphonates resulted in the formation of the corresponding bis(a-hydroxyalkylphosphonate)s [185]. 

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