ALKYL-OXYGEN BOND CLEAVAGE IN TRITYL ACETATE-18O DURING REACTION WITH PHENYL GRIGNARD REAGENT

Triphenylmethyl (trityl) acetate-18O and phenylmagnesium bromide (1:1.3 molar ratio) react in ether at room temperature. Trityl peroxide and acetic acid are the major products detected in the reaction mixture after hydrolysis in the presence of air. Acetophenone, triphenylmethane, benzophenone, triphenylmethanol, tetra phenylmethane, and very small quantities of several other compounds were also identified by glpc and mass spectral analysis. Since trityl peroxide did not contain 18O, a classical acyl-oxygen [C(=O)O] bond cleavage was considered untenable. The acetic acid examined contained 18O in the amount essentially identical with that determined in trityl acetate-18O used as starting material. A mechanism is postulated to involve electron transfer by the Grignard reagent to trityl cation to give trityl radical. © 1969, American Chemical Society. All rights reserved.