1,2-Epoxy alkanes from C3 to C8 were reacted with DNA, deoxyguanosine and 4-(p-nitrobenzyl) pyridine (NBP). DNA was hydrolyzed at neutral pH to release 7-alkylguanines. The products were analyzed by HPLC. The epoxides reacted largely according to the chain length, shorter epoxides being more reactive. Substitutions through carbon 1 predominated. Reactivity with NBP was almost equal between the epoxides.