(2R,2'R,5R,5'R)-1,1'-(1,2-ethanediyl)bis-[2,5-dimethylphospholane]; (2R,2'R,5R,5'R)-1,1'-(1,2-ethanediyl)bis[2,5-diethylphospholane]; (2S,2'S,5S,5'S)-1,1'-(1,2-ethanediyl)bis[2,5-di(2-propyl)phospholane] and (2S,2'S,5S,5'S)-1,1'-(1,2-ethanediyl) bis[2,5-dimethylphospholane]; (2S,2'S,5S,5'S)-1,1'-(1,2-ethanediyl)bis[2,5-diethylphospholane]; (2R,2'R,5R,5'R)-1, 1'-(1,2-ethanediyl)bis[2,5-di(2-propyl)-phospholane]
Hutchinson, Douglas K., e-EROS Encyclopedia of Reagents for Organic Synthesis, 2014, 1, 1-5