Trifluorolactate

A spiro adduct is the result of the reaction of diazofluorene and perflu-oro-2-butyne (72AG(E)224, 72TL3479 74CB2027). With diazomethane and ethyl diazoacetate the above-mentioned trifluoromethyl-substituted alkynylamino and alkynyl hydroxy acid esters give a single [3 -t- 2] cycloadduct, namely the 2-(3-pyrazolyl)-3,3,3-trifluoroalanine and the 2-(3-pyrazolyl)-3,3,3-trifluorolactic acid derivatives, respectively (92LA947) (Scheme 71). 

Katagiri, T. and Uneyama, K. (2001) Chiral recognition by multicenter single proton hydrogen bonding of trifluorolactates. Chem. Lett., 1330-1331. 

Figure 4.3 A schematic view of hydrogen-bonding system of isopropyl trifluorolactate.

The yields of trifluoropyruvic thioamides 6 with common secondary amines are mostly fair and do not exceed 65 %. The reduction products - trifluorolactic thioamides 7 are formed in certain cases as by-products (about 5 %). Trifluoroacetone yields under the Willgerodt-Kindler conditions only 7 (30-35 %), besides other products. These lactic products 7 are therefore formed more expediently by reduction of 6 using ammonium formate at 100°C. 

Trifluorolactic acid. This compound can be prepared from l,2-epoxy-3,3,3-trifluoropropane in a Cu-catalyzed oxidation. 

Ring opening of 34 with either acidic or nucleophilic reagents occurs at the unsubstituted carbon to give optically active alcohols, for example, hydroxysulfide 37 formed from phenylthiolate ion generated in situ. Oxidation of oxirane 34 yields trifluorolactic acid (38) without any loss of optical activity. ... 

Previously we pointed out that the oxidation of alkenes in water allows one-pot multi-step reactions to be carried out involving tandem epoxidation and ring-opening reactions. Further examples are the synthesis of optically active trifluorolactic acid by aqueous nitric acid ring-opening oxidation of (-)-l,2-epoxy-3,3,3-trifluoropropane [19] in the presence of a catalytic amount of copper metal ... 

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