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. (C) 2002 Elsevier Science Ltd. All rights reserved.