| 摘要 |
NEW MATERIAL:A compound shown by the formula I (R<1>-R<4> are H, alkyl, or R<1> and R<3> may be linked to form ring; R<5> is lower alkyl). EXAMPLE:3,3-Difluoro-4-hexadecenoic acid methyl ester. USE:An intermediate for synthesizing especially a beta,beta-difluoro saturated carboxylic acid, a beta-oxidation inhibitor to inhibit beta-oxidatation in substance metabolism in a biochemical field. PREPARATION:For example, an alpha-acetoxyaldehyde or ketone shown by the formula II is difluoromethylated with (Me2N)3P and CF2 Br2 in a solvent such as tetrahydrofuran, etc., to give a compound shown by the formula III, which is then saponified to give a 1,1-difluoro-1-alkene-3-ol shown by the formula IV. This compound is subjected to Claisen rearrangement in a solvent such as toluene, etc., in the presence of R<4>CH2C(OR<5>)3 and a propionic acid CH3CH2 COOH acid to give a compound shown by the formula I.
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