The application is directed to compounds of Formula Iand pharmaceutically acceptable salts and solvates thereof, wherein Cy, R1-R3, R4a, and R4b are defined as set forth in the specification. The invention is also directed to use of compounds of Formula I to treat disorders responsive to the modulation of one or more opioid receptors, or as synthetic intermediates. Certain compounds of the present invention are especially useful for treating pain.本申請案係關於式I化合物及其藥學上可接受之鹽及溶劑化物，其中Cy、R1-R3、R4a、及R4b為如同專利說明書中所定義者。本發明亦關於式I化合物於治療對一或多種類鴉片受體之調節有反應之失調、或作為合成中間體的用途。某些本發明化合物尤其可用於治療疼痛。
