This invention relates to a novel class of compounds, diagrammed below, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, D and n are defined therein, which are cysteine protein inhibitors, including, but not limited to, inhibitors of cathepsins K, L, S and B. These compounds are useful for treating diseases in which inhibition of bone reportion is indicated, such as osteoporosis.