Synthesis of Enantiopure α-Alkoxy-α-Trifluoromethyl Aldehydes and Carboxylic Acids from Trifluoromethyl Ketones

Formaldehyde dialkylhydrazones behave as neutral d¹ synthons in their uncatalyzed reaction with trifluoromethyl ketones (see reaction). Both racemic and optically pure 1,2-adducts were obtained in good yields. Efficient deprotection of the hydrazone moiety afforded interesting fluorinated quaternary compounds such as 1 and 2 .