1-hexanethiol conversion to 6-Mercaptohexanoic acid is the selective oxidation of a primary C-H in the presence of a very easily oxidizable thiol group, which is practically impossible
Why you choose the synthesis of 6-Mercaptohexanoic acid form starting material 1-hexanethiol. Is there any specific reason. Please let me know. If you want to synthesis of 6-Mercaptohexanoic acid choose other starting material instead of 1-hexanethiol. If you want to make from 1-hexanethiol it may take more number of steps and less yield.