(-)-2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphanyl)butane; tetrakis(triphenylphosphine) palladium(0) in tetrahydrofuran T=0°C; 14 h; Yields of byproduct given;

1,2-bis-(diphenylphosphino)ethane; Pd(1,2-bis(diphenylphosphino)ethane)2 in tetrahydrofuran T=0°C; 16.5 h; Yield given. Yields of byproduct given;