Stereoselective construction of functionalized (Z)-fluoroalkenes directed to depsipeptide isosteres

Cu(I)-mediated alkyl-transfer reaction of trialkylaluminum (R3Al) with (E)- or (Z)-4,4-difluoro-5-hydroxyallylic alcohol derivatives proceeded in an SN′-type manner to give the corresponding 2-alkylated (Z)-4-fluoro-5-hydroxyhomoallylic alcohol derivatives with 2,5-syn- or 2,5-anti selectivity, respectively. Oxidation of the primary hydroxyl group of the product to carboxylic acid was easily achieved without epimerization at the chiral centers.