The present invention pertains to certain ketones and reduced ketones and derivatives thereof which, inter alia, inhibit osteoclast survival, formation, and/or activity; and/or inhibit bone resorption, and more particularly to compounds of the formulae and pharmaceutically acceptable salts, amides, esters, and ethers thereof, wherein: Ar1, R.sup.alk, --ORO, and -Q are as defined herein: ##STR00001## The present invention also pertains to pharmaceutical compositions comprising such compounds. The compounds inhibit osteoclast survival, formation, and/or activity, and inhibit conditions mediated by osteoclasts and/or characterised by bone resorption, and are useful in the treatment of bone disorders such as osteoporosis, rheumatoid arthritis, cancer associated bone disease, Paget's disease, aseptic loosening of prosthetic implants, and the like; and/or in the treatment of conditions associated with inflammation or activation of the immune system.