Barium trifluoroacetates

This intermediate was alkylated with tert. -butyI-cj-iodohexanoate to the ester 30. Conversion to the acid 31 was achieved by cleavage of the fed.-butylester with trifluoroacetic acid at low temperature. The triple bond was reduced to a trans-double bond and simultanously the benzylether groups had been removed with lithium in ethylamine, under formation of the desired 15-deoxy-7-oxaprostaglandin Fla 32 in crystalline form. The ds-isomer was prepared by first reducing the triple bond of compound 30 with palladium on barium sulfate to 33, removal of the ted. -butylgroup with formic acid to 34 and debenzylation of the acid with lithium in ethylamine to 35. 

Alkylation of dimethyl ( S)-malate (2) at oxygen can be accomplished with an alkyl halide in the presence of silver oxide. The methoxy derivative 7a forms in 74% yield [3], while the benzyloxy analog 7b is produced in 84% yield [12]. Alternatively, 7b can be prepared by treating 2 with (9-benzyl trichloroacetimidate in the presence of trifluoroacetic acid (68% yield) [13]. Upon treatment of malate ester 7a with barium hydroxide, (iS)-methoxysuccinic acid (8) is obtained in high yield [3]. 

Barium bis-(3-triiluoroacetylcamphorate) is easily obtainable through addition of barium chloride solution to the product of a Grignard reaction between ( + )-3-bromocamphor and ethyl trifluoroacetate. Treatment of Ba(tfacam)3 with (COlaRhjClj in chloroform yields the rhodium chelate (39),i68,i6 which shows promise as a gas-chromatographic stationary phase for olefin separations. - Data are also available regarding the use of solutions in squalane of other Ln(tfacam)g chelates as stationary phases for g.l.c. analysis of nucleophilic organic substrates. ... 

Using this chemical phenomenon, heavy-metal fluoride glasses were prepared using trifluoroacetates of zirconium, barium, lanthanum, aluminum and sodium [21]. Eigure 10.2 shows thermal gravimetric analysis of the ZBLAN powder in this process. A drastic decrease in weight (47.4%) was observed in the range of 220-300 °C, which was attributed to the decomposition from the trifluoroacetate to the sohd ZBLAN fluoride. 

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