Synthesis of hexahydrochromeno[4,3-b]azepine derivatives

Synthesis of optically pure (6aR,11aS)-7,8,9,10,11,11a-hexahydro-5-oxa-11-azacyclohepta[a]naphthalen-6a-ylamine from 2-cyano-6-oxazolopiperidine is described via the CN(R,S) strategy. The lithium aluminium hydride involves a one-pot reduction and a ring-enlargement process. Absolute configuration of the tricyclic derivative is unambiguously established by X-ray crystal structure analyses.