A solvent effect in the reaction of diazomethane with norbornane-2,3-dione 3-hemiketal in various aprotic solvents such as ether, dichloromethane, tetrahydrofuran (THF), dioxane, and chloroform is reported. Unlike in methanol, preparatively useful quantities of oxetane derivatives were obtained along with a novel hexahydro-1H-cyclopenta[c]furan-1-one in these aprotic solvents. Dichloromethane and THF gave optimal yields of the two products. In some cases, α-ketoketals were formed as minor products along with the aforementioned products. Interestingly, TMSCHN2 furnished hexahydro-1H-cyclopenta[c]furan-1-one as the predominant product. © 2014 Copyright Taylor & Francis Group, LLC.