New synthetic phosphinate analogues of lecithin.

The chemical syntheses of two new, completely nonhydrolyzable phosphinate analogues of lecithin are described. These have the structures ROCH(2)CH(OR)CH(2)CH(2)P(O)(O(-))CH(2)CH(2)N(+)(CH(3))(3) and ROCH(2)CH(OR')CH(2)P(O)(O(-))CH(2)CH(2)CH(2)N(+)(CH(3))(3), where R = C(18)H(37) and R' = C(16)H(33); each is thus isosteric with lecithin on either side of the phosphorus function. The infrared spectra of these compounds undergo unexpected changes under mild acid, base, or adsorptive treatment. These are discussed and compared with related lecithin analogues, including the simple phosphinate C(18)H(37)P(O)(O(-))CH(2)CH(2)N(+)(CH(3))(3), whose synthesis is also reported.