Methyl diphenylphosphinite

The reaction of methyl diphenylphosphinite with benzaldehyde and acetic acid leads to the formation of acylals (cf. Houben-Weyl, Vol. E2, p 11). When the reaction is performed under mild conditions (room temperature), only one diastereomer 4 is formed the proposed route is illustrated in the scheme29. 

Methyl diphenylphosphinite and u-hydroxycinnamic acid gave the bicyclic acyloxy-phosphorane (52). This rearranged above its melting point to give the coumarin (54) and was hydrolysed rapidly to give the phosphine oxide (53). 

The synthesis of novel phosphorane structures continues to be fashionable. When methyl diphenylphosphinite is heated with 2-hydroxycinnamic acid, the spirobicyclic acyloxyphosphorane (79) is formed. (See also Chapter 2). The now well established reaction of the tervalent phosphorus with compounds containing two suitably... 

Stork and Isobe have used this hydroxymethylation reaction for two prostaglandin syntheses. In one the starting material is the oxide of cyclopenta-diene, which is converted in several steps into (1). Reduction of (1) with methyl diphenylphosphinite gives the enol phosphinate (2), which is cleaved by t-... 

Phosphoranes (91) have been prepared in 21—90% yield by the reaction of (89) with various three-co-ordinated phosphorus compounds (90). A detailed study of the reaction between methyl diphenylphosphinite and 1-nitropropene shows that at ca. — 5 °C a quantitative yield of the monocyclic phosphorane (94)... 

Similar nucleophilic substitution at phosphorus with the loss of alkoxide instead of halide vide supra) also occurs readily. Thus, under a nitrogen atmosphere (to avoid oxidation at phosphorus) when four or more equivalents of phenylmagnesium bromide are treated with trimethyl phosphite (Equation 10.75), triphenylphosphine is cleanly obtained. However, if three or fewer equivalents of the same Grignard reagent are used, then dimethyl phenylphosphonite, methyl diphenylphosphinite, and triphenylphosphine are all found (Equation 10.76) with the exact ratio being. 

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