I'm trying to make an aliphatic carboxylic acid with a trifluro group at the alpha position. So far I have used trifluoromethyl pyruvate and reacted that with an ylide. I can form the unsaturated ester and reduce it. When it comes to hydrolysis of the ester using a mild base, I get elimination of the fluorine. The hydrolysis doesn't work with an acid, nor can I hydrolyse the unsaturated methyl ester first and then reduce the double bond.
I have found a way round this by reducing the ester to the alcohol and then to oxidise this back up but this seems like a long winded process of something that should be quite simple. Any suggestions will be very gratefully received!