Morphine contains 5 chiral centers and has 16 optical isomers (not 32 because of the restriction of C-9 to C-13 Ethan amino bridge). The naturally occurring, active form of morphine is the levorotatory enantiomorph with the stereochemistry 5( R), 6(S), 9(R), 13(S), and 14 (R). The x-ray determined conformation of morphine is a “T” shape with the A, B, and E rings forming the vertical portion, and the C and D ring forming the top.
