Synonyms: 9,9-dimethyl-4,5-bis(diphenylphosphino)-9H-xanthene;9,10a-dihydro-9,9-dimethyl-4,5-bis(diphenylphosphino)-8aH-xanthene;Phosphine,(9,9-dimethyl-9H-xanthene-4,5-diyl)bis[diphenyl- (9CI);(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis[diphenylphosphine];4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene;9,9-Dimethyl-4,5-bis(diphenylphosphino)xanthene;Xantphos;