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

Angew Chem Int Ed Engl. 1998 Dec 31;37(24):3428-3430. doi: 10.1002/(SICI)1521-3773(19981231)37:24<3428::AID-ANIE3428>3.0.CO;2-P.

Abstract

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.

Keywords: Asymmetric synthesis; Chiral auxiliaries; Fluorine; Hydrazones; Nucleophilic additions.