The reaction of salicylaldehyde with 1-phenyl-1-methyl-3-(2-chloro-1-oxoethyl) cyclobutane (1) and potassium carbonate was used to prepare (benzofuran-2-yl)(3-methyl-3-phenylcyclobutyl) methanone (2) for the starting reagent purposes. (benzofuran-2-yl)(3-phenyl-3methyl cyclobutyl) ketoxime (3) was synthesized from the reaction of the compound (2) with hidroxylamine. New derivatives of (benzofuran2-yl)(3-phenyl-3-methyl cyclobutyl) ketoxime (3) such as, O-glycidylketoxime (4) and O-phenylacylketoxime (5a-c) were obtained very high yields. Alkyl, allyl and aryl substituted N-oxime ethers (6a-e) were obtained from the reaction compound 3 and various halogen contained compounds. The syntheses of the compounds (7a-f) were carried out from the reaction of the compound (4) and different an-tines such as, isopropyl amine, natrium azide, morpholine and piperazine. All of the synthesized compounds were tested for antimicrobial activity against Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Salmonella typhi, Shigella flexneri, Proteus mirabilis ATCC 14153 and Candida albicans ATCC 10231. Among the synthesized compounds (benzofuran-2-yl)(3-phenyl-3-methyl cyclobutyl)-O-[2-hydroxy-3-(Nmethylpiperazino)] propylketoxime (7d) was found the most active derivative against S. aureus ATCC 6538. The compounds 2,5b, 6b, 6c, 7b and 7f showed very strong and the same antimicrobial effect against C albicans ATCC 10231. Similarly (benzofuran-2-yl)(3-phenyl-3methylcyclobutyl)-O-benzylketoxime 6a showed good antimicrobial effect against C. albicans ATCC 10231. None of the other compounds exhibited activity against the other test microorganisms. (c) 2005 Elsevier SAS. All rights reserved.