Chiral Synthesis of McGeachin-Type Bisaminals.

Bridged [3.3.1]-bisaminal structures, namely 6,12-epiminodibenzo[b,f][1,5]diazocines, are herein named McGeachin-type bisaminals. The TsOH-catalyzed chiral synthesis of McGeachin-type bisaminals is first developed by condensation of two molecules of 2-(methylamino)benzaldehyde and one molecule of chiral amines. Two chiral diastereomers are generated simultaneously and are isolated by column chromatography in a total yield of up to 99%. The absolute structure of one stereoisomer was determined by X-ray crystallography.