Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... The synthesis of tetracyclo[5.4.1.0 4,12 .0 9.12 ]dodecan-6-one via an intramolelecular photocycloaddition, its reduction to the hydrocarbon and its ring-contraction to tetracyclo-[4.4.1.0 3,11 .0 9,11 ]undecane derivative is described.