Question

Determine the R/S orientation of the indicated carbons in this molecule

Determine the R/S orientation of the indicated carbons in this molecule. Carbon a: Carbon b: Carbon c: Carbon d:

Answer 1

The structure of the compound is as follows H2C 3 он H2C 3 CH Identify the chiral center Assign priority to ther groups around the chiral center based on the atomic number See the rotation around the stereocenter. If the rotation is clockwise, it is R configuration and if the rotation is anticlockwise, the configuration is S NOTE :If the least priority group is above the plane, then reverse the configuration that is obtained The chiral center is a Cl is given priority 1, OCH3 as 2, and CH3 as 3 The direction of rotation is clockwise. The configuration should be R. But the highest priority group is behind the plane. Hence, the configuration is reversed. Therefroe, the configuration at a is S The chiral center is b OH is given priority 1, C at a as 2, and C at c as 3 The direction of rotation is clockwise. The configuration should be R. Therefroe, the configuration at b is R. The chiral center is c OH is given priority 1, C at b as 2, and C at d as 3 The direction of rotation is anticlockwise. The configuration should be S Therefroe, the configuration at c is S The C at d has no configuration because, it is not a chiral center Carbon a:S Carbon b:R Carbon c:S Carbon d: Achiral