Similarly, sometimes steric assistance increases the rate of a reaction. The phenomena can be seen in the ester hydrolysis of conformationally locked cyclohexane derivatives. In the ester hydrolysis the rate limiting slow step is the formation of sp3 hybrid intermediate by the nucleophilic addition on the trigonal carbonyl group. This imparts some steric bulk to the intermediate as well as decreases its degree of solvation as the species is now negatively charged. Thus, on going from the ester to the intermediate, the steric requirement of the ester group increases as it passes through the transition state. As a result, the difference in free energies of the axial and equatorial isomers is enhanced in the transition state than in the ground states and the axial isomer reacts at a slower rate. This is an example of steric hindrance. However, in the chromic acid oxidation of cyclohexyl alcohols a different scenario. This reaction is supposed to consist of two steps, the rapid formation of a chromate ester followed by its rate determining decomposition into a ketone. In this case the axial alcohols are oxidized faster than their equatorial isomers. This occurs because the difference in free energies between the axial and the equatorial chromate esters in the ground state exceeds that between the respective transition states due to more ketone like structure of the latter.