From cyclooctatetraene to chiral polyfunctionalized C8 building blocks—meso-persubstituted oxepanes and azepanes

Cyclooctatetraene—via its 1α,2α,5α,6α-diepoxy-3β,4β-diol (4)—is the basis for the construction of specifically polyfunctionalized C8 building blocks. Whilst with monofunctional nucleophiles only monosubstitution and with 1,1-dinucleophiles neatly intramolecular cyclization to aza(oxa,thia)bicyclo[4.2.1]nonenes occurred, the desired substitution pattern became, in principle, accessible with 1,2-disubstituted hydrazines. The usefulness of the 7-hetero[4.2.1]bicycles for the preparation of meso-persubstituted azepanes and oxepanes is exemplified.