Finally, we examined ring expansion as an entry to alternative scaffolds and again both the urea and the cyclohexanone rings embedded in spirotricycles 2 were targeted. Formal insertion of a methylene unit to the urea was achieved by reaction of the diamine 12b with complementary α-haloacetic acid derivatives (Scheme 4, panel A). Thus, reaction with chloroacetyl chloride proceeds directly to piperazinone 15b, presumably via initial acylation of the pyrrolidine followed by internal substitution of the aliphatic carbon by the less nucleophilic aryl amine. The regiocomplementary outcome could be achieved by initial alkylation of the pyrrolidine with methyl bromoacetate, followed by base-mediated amidation to give 16b. Ring expansion of the saturated ketones 4a-c was achieved by Beckmann rearrangement, giving the tricyclic lactams 17a-c (Scheme 4, panel B). The reactions were unexpectedly regioselective: lactam 17a was formed as a 93:7 mixture of regioisomers as judged from the crude 1 H NMR, but isolated as a single compound, whose structure was determined crystallographically. Lactams 17b/c gave slightly less regioselective rearrangements (3:1 and 2:1 in the 1 H NMR of the crude) but were isolated as predominantly the isomer shown. In an attempt to access the regiocomplementary lactams, we examined the Beckmann rearrangement of the cyclopropyl ketones 4a/b, reasoning that substitution in the form of the cyclopropyl group might bias the oxime geometry to place the leaving group anti-to the moresubstituted carbon. In the event, however, migration of the other carbon was still favoured, giving 18a/18b as the predominant isomers, albeit with significant formation of the isomeric products 18a' and 18b'.