Wurtzitan (Tetracyclo[5.3.1.12,6.04,9]dodecan)

A new synthesis of wurtzitane (13) is described starting from 2-oxo-protoadamant-4-ene (2). The key intermediate ketone 7 was obtained by regiospecific ring expansion of the β-amino alcohol 6. Entry to the wurtzitane system involved solvolysis of the tricyclic unsaturated mesylate 10 (11).