Efficient Entry to Diastereo- and Enantiomerically Pure (alpha)-Branched [2.2]Paracyclophanyl-alkylamines

The preparation of diastereo- and enantiomerically pure (alpha)-branched [2.2]paracyclophanyl-alkylamines is reported. Key step is the nucleophilic 1,2-addition of various alkyllithium reagents to either enantiomer of 4formyl[2.2]paracyclophane-N,N-dimethyl-hydrazone obtained by resolution (HPLC). The resulting hydrazines were converted to the corresponding amines by reductive N-N bond cleavage. Reaction with CbzCl gave both enantiomers of the N-Cbz-protected diastereo- and enantiomerically pure (de, ee >99%) title compounds in good yields, respectively.