The title bis(phosphane) ligands have been prepared starting from optically pure diisopropyl (P)-and (M)-8,12-diphenylbenzo[a]heptalene-6,7-dicarboxylates ((P)-1b and (M)-1b) that had been obtained by HPLC separation of rac-1b on a semi-preparative Chiralcel OD column. Reduction of (P)-1b and (M)-1b with diisobutylaluminum hydride (DIBAH) gave optically pure (P)-and (M)-dimethanols 3 (Scheme 6 and Fig. ). Unfortunately, the almost quantitative chlorination of rac-3 with PCl 5 in CHCl 3 at À 608 led with (M)-3 to nearly complete loss of optical integrity. However, mesylate formation of (P)-3, followed by phosphanylation with LiP(BH 3 )Ph 2 gave (P)-6 with only a small loss of optical activity. Optically pure (P)-6 was obtained by crystallization from Et 2 O/hexane, which removed the nearly insoluble rac-6. The pure bis(phosphane) ligands (P)-2 and (M)-2 can be liberated quantitatively from 6 by warming 6 in toluene in the presence of 1,4diazabicyclo[2.2.2]octane (DABCO). First Rh I -catalyzed asymmetric hydrogenation reactions of (Z)-a-(acetamido)cinnamic acid ((Z)-14) in the presence of (P)-2 led to (R)-N-acetylphenylalanin ((R)-15) in optical purities up to 77% (see Table ).