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 herein.Compounds of the Invention are useful for treating pain, constipation, and other conditions modulated by activity of opioid and ORL-1 receptors.