A subrule of the Cahn-Ingold-Prelog system specifies that higher mass number takes precede...

A subrule of the Cahn-Ingold-Prelog system specifies that higher mass number takes precedence over lower when distinguishing between isotopes.

(a) Determine the absolute configurations of the reactant and product in the biological oxidation of isotopically labeled ethane described in Section 7.2.

(b) Because OH becomes bonded to carbon at the same side from which H is lost, the oxidation proceeds with retention of configuration (Section 6.14). Compare this fact with the R and S configurations you determined in part (a) and reconcile any apparent conflicts.