Chemoselectivity and protecting groups

This chapter describes chemoselectivity and protecting groups. Most organic molecules contain more than one functional group, and most functional groups can react in more than one way, so organic chemists often have to predict which functional group will react, where it will react, and how it will react. These questions are what can be called selectivity. Selectivity comes in three sorts: chemoselectivity, regioselectivity, and stereoselectivity. The chapter focuses on chemoselectivity (which group reacts). It begins by looking at reductions of carbonyl compounds, introducing a few more specialized reducing agents. The chapter then considers the other type of reduction in the salmefamol synthesis: catalytic hydrogenation.