Siloxycarbenes, formed by the photolysis of dimethyl- or diphenylsilacyclohexanone have been trapped as oxiranes or as the ring-opened hydrolysis products of oxiranes, with simple aldehydes and ketones such as acetaldehyde, or cyclohexanone. The reactions are interpreted as arising from the nucleophilic attack of the siloxycarbene on the carbonyl group. The structures of the oxiranes and their hydrolysis products have been established.