(2R,3R)-Bis(diphenylphosphino)butane

(R,R)-2,3-Bis(diphenylphosphino)butane; (R,R)-Chiraphos; CIRA; [R-(R*,R*)]-(1,2-dimethyl-1,2-ethanediyl)bis[dipheplphosphine; [(1R,2R)-1,2-dimethyl-1,2-ethanediyl]bis[diphenylphosphine;