question_answer 66)

  The letters 'D' or 'L' before the name of a stereoisomer of a compound indicates the correlation of configuration of that particular stereoisomer. This refers to their relation with one of the isomers of glyceraldehyde. Predict whether the following compound has 'D' or 'L' configuration.

Answer:

                  Since the orientation of the OH group at the penultimate chiral carbon (i.e., last but one or ) is towards left, therefore, the given compound has L-configuration.