A process for producing allylic ether compounds in presence of a catalyst comprising at least one Cu salt by reaction of an allylic alcohol with either itself or another alcohol. The present invention provides a medicine packaging sheet including a barrier layer and an oxygen absorbing layer, wherein the oxygen absorbing layer is composed of a resin composition including a base resin, an oxygen absorbing resin, and a reaction accelerator. A short-term private key is provided for use by a computing entity in effecting cryptographic operations during an operational period. Also disclosed is an embodiment where two angle gear boxes are used as a power-receiving transmission, with the result that all of the mowing units can be constructed exactly the same.