... of Chemistry, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, UK. Chem. Res. ... Chemicals. 3-Chloroperoxybenzoic acid (m-CPBA) 1 and butadiene monoxide (ethenyloxirane) were purchased from Aldrich Chemical Co. (Poole, Dorset, UK). ...