Bicyclo[9•4•1]hexadecan-16-one is prepared from cyclododecanoneviafour steps: ethoxycarbonylation, condensation with 1,4-dibromobutane, saponification, and decarboxylation. Photolysis of the bicyclic ketone yields a ketene which is trapped with methanol to afford methyl cyclopentadecanecarboxylate or alternatively oxidized to exaltone directly. The ester is also converted into exaltoneviafive steps.dl-Muscone is prepared by applying the same scheme to cyclotridecanone with 14-methylbicyclo-[10•3•1]hexadecan-16-one as the key intermediate.