As Problem 50 indicates, the enzymatic reactions that introduce functional groups into the steroid nucleus in nature

Question:

As Problem 50 indicates, the enzymatic reactions that introduce functional groups into the steroid nucleus in nature are highly selective, unlike the laboratory chlorination described in Problem 51. However, by means of a clever adaptation of this reaction, it is possible to partly mimic nature's selectivity in the laboratory. Two such examples are illustrated below.

Propose reasonable explanations for the results of these two reactions. Make a model of the product of the addition of Cl2 to each iodocompound (compare Problem 51) to help in analyzing each system.