Organic Phosphorus Compounds 52 . Preparation and properties of β‐hydroxyalkyl‐phosphonium salts and tertiary phosphine oxides

The new, tris‐ (2‐ hydroxyalkyl) ‐ (hydroxymethyl) ‐ phosphonium salts: [(RCHOHCH 2 ) 3 PCH 2 OH]Cl (I, R = ClCH 2 ; III, R = CH 3 ) are formed in high yield by reaction of tetrakis‐(hydroxymethyl)‐phosphonium chloride (Tetrakis) with epoxides under basic conditions. Under the same conditions, styrene oxide yields only the disubstituted product, [(PhCHOHCH 2 ) 2 (CH 2 OH) 2 P]Cl. Optimal pH values for the reactions are 8 to 9; at lower pH the conversion is too slow; at a higher pH, oxidative decomposition of the salts occurs. Conversion of the salts to tertiary phosphine oxides (RCHOHCH 2 ) 3 P O (R ClCH 2 ; CH 3 ) with loss of the hydroxymethyl group is best carried out with chlorine at pH 5 to 7. The yields are usually 60 to 90%.