PROTECTING GROUPS - Intro and Protection of Hydroxyl Functional group

Protecting  groups  are  the  derivatives  that  are  installed  temporarily  to mask  the  reactivity  of  a functional  group in a multifunctional compound to achieve a chemoselective reaction. The required characteristics for a protecting group includes –

• Obtaining  the  chemoselectivity  in a  subsequent  chemical  reaction
• In a compound  containing  multifunctional  groups  when the chemical  reaction is  to be carried out  selectively  at one reactive site, other  reactive sites must  be temporarily  blocked.
• Introduction and removal of the protective group must be efficient.

        The functional groups which are widely used for protection are Hydroxyl group (-OH), Carbonyl group (-C=O), Thiol group (-SH), Carboxylic acid group (-COOH), Phosphate group (-PO₄^3-), Amino group (-NH₂) and Alkyne derivative.

PROTECTION OF HYDROXYL GROUP (-OH) :

The following chart gives you a proper outline of various routes of protecting Hydroxyl functional group.