A process for opening naphthenic rings of naphthenic ring-containing compounds, along with catalysts which can be used in that process. The naphthene ring opening catalyst is a catalyst comprising at least one Group VIII metal selected from Ir, Pt, Rh, and Ru, wherein these metals are supported on an alkali metal or alkaline-earth metal modified support in an amount effective for opening a naphthene ring-containing compound at a tertiary carbon site.