AbstractThe effects of the steric environment of the epoxy group on the curing and other properties of epoxy resins containing 3‐oxatricyclo [3,2,1,02,4]oct‐6‐yl and 4‐oxatetracyclo[6,2,1,02,7,03,5]undec‐9(or 10)‐yl residues were examined. During the anhydride cure of certain members of the former class, evolution gas was observed. This is attributed to intramolecular reaction between the epoxide group and the linkage between the two ring systems. Stereoselectivity in epoxidation of tricyclo[5,2,1,02,6]undec‐3‐en‐8(or 9)‐yl derivatives is high, and the two possible series of stereoisomers were obtained, by epoxidation with peracetic acid and by formation and saponification‐dehydrochlorination of chlorohydrin‐acetates, respectively. The relative reactivities of the two stereoisomeric series were examined. The routeviathe chlorohydrin is not applicable to epoxidation of dehydronorbornyl derivatives, owing to the occurrence of rearrangements.No analogous stereochemical effects were observed with cyclohe