The application provides compounds of Formula I and pharmaceutically acceptable salts and solvates thereof, wherein R1, R2, R3, R4, R5, dash line a, dash line b, W, Z, X, and m are defined as set forth in the specification. The invention is also directed to use of the compounds of Formula I and the pharmaceutically acceptable salts and solvates thereof to treat disorders responsive to the modulation of one or more opioid receptors, or as synthetic intermediates. In certain embodiments, the Compounds of the Invention are useful for treating pain.
