The syntheses and in vitro pharmacological evaluation of a number of cis-3, 4-diaryl-hydroxy- chromanes are reported, along with the results of a thorough in vivo profiling of the tissue- selective estrogen partial-agonist NNC 45-0781 [3,(−)-(3S, 4R)-7-hydroxy-3-phenyl-4-(4-(2- pyrrolidinoethoxy) phenyl) chromane]. These studies showed that NNC 45-0781 is a very promising candidate for the prevention of post-menopausal osteoporosis, and the ...