Preparation of 2, 2'-Dihydroxytriphenylmethanes Using Metal Phenolates with Aromatic Aldehydes

The reactions of exophilic metal phenolates having electron-donating substituent (1a-c) with aromatic aldehydes (2, 3) were selectively condensed at the ortho-position of the starting phenol to afford 2, 2'-dihydroxy-triphenylmethanes (8-11). This method was also applicable to the preparation of bisphenols (12-17) starting with naphthaldehydes (4, 5) and pyridinecarboxyaldehydes (6, 7), but in low yields. In the case of these aldehydes (4-7), satisfactory yields could be obtained by sonication.