The mass spectra of methoxycycloalkanes and methoxymethoxycycloalkanes

Mass spectra of methoxycycloalkanes (CH3OR, R C5 to C8) and of methoxymethoxycycloalkanes (CH3OCH2OR, R C5 to C8, C12) have been compared with each other and with spectra of some steroidal analogues. It is concluded that the different fragmentation occurring in dimethoxymethane indicates decomposition before randomisation of excess energy.