Versuche zur Synthese von α,β‐ungesättigten trifluormethylierten Aldehyden

Abstract

Efforts in Synthesizing α,β‐Unsaturated Trifluoromethyl‐substituted AldehydesHexafluoroacetone reacts with ethynylmagnesium bromide to yield (CF3)2C(OH)  C  CH (1). Bromine can be added to the triple bond affording the cis/trans‐isomer 2. With PCl5 1 yields the allene (CF3)2CCCClH (3). The addition of a metalated Schiff base to hexafluoroacetone leads to 4a which on hydrolysis yields (CF3)2C(OH)  CH2  CHO (4b). The reaction of (EtO)2P(O)CH2  R (RCHO, CO2Et) with hexafluoroacetone gives α,β‐unsaturated aldehydes or esters 6. 1,1,1‐Trifluoroacetone provides analogous reactions.