Process for preparing 3-(3,5-di-tert.alkyl-4-hydroxy-phenyl)-2,2-di-substituted propionaldehydes

A process comprising reacting a compound having the general structural Formula II:

• ##STR18## with a compound having the general Formula III:
• ##STR19## in the presence of a catalyst selected from the group consisting of alkali metal hydroxides and alkali metal alkoxides while dissolved in an organic solvent selected from the group consisting of aliphatic alcohols, aliphatic ethers and aliphatic nitriles to yield an aldehyde having the structural Formula I:
• ##STR20## wherein R.sub.1 and R.sub.2 are the same or different radicals selected from the group consisting of tertiary alkyl radicals having from 4 to 12 carbon atoms, R.sub.3 and R.sub.4 are the same or different radicals selected from the group consisting of alkyl radicals containing from 1 to 12 carbon atoms, cycloalkyl radicals containing from 5 to 12 carbon atoms and phenyl radicals or R.sub.3 and R.sub.4 with the carbon atoms to which they are joined may form a cycloalkyl ring of from 5 to 12 carbon atoms, R.sub.5 is selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, or a cycloalkyl radical containing 5 to 6 carbon atoms.