The present invention is directed to Benzomorphan Analog compounds of the Formula I", Formula IA", Formula IB", Formula IC", or Formula ID" as shown below; and related Formula I', Formula IA', Formula IB', Formula IC', or Formula ID'; Formula I, Formula IA, Formula IB, Formula IC, or Formula ID;wherein R1, R2a, R2b, R3 and R4 are as defined hereinCompounds of the Invention are useful for treating pain, constipation, and other conditions modulated by activity of opioid and ORL-1 receptors.