The principal products of radiolysis of 1-(2-furanyl)-1-pentanone (FP) in 2-propanol in the presence of atmospheric oxygen were determined using a gas chromatograph coupled with a mass spectrometer. The principal products detected were:1-[2-(5-hydroxy-4-hydro) furanyl]-1-pentanone (HHFP), and 1-[2-(5-hydroxy-4-methyl) furanyl]-1-pentanone (HMFP).The radiation yield G has been determined and mechanisms for the formation of the radiolytic products are proposed.