Synthesis of cyclic acetals and cyclic ketals:

Both of the synthesis and the hydrolysis of acetals and ketals can be performed in high yield and thus these functional groups are very good as protecting groups for aldehydes and ketones. Acetals and ketals are stable to nucleophiles and essential conditions and thus the carbonyl group is 'disguised' and will not react with these reagents. Cyclic acetals and ketals are best employed for the protection of aldehydes and ketones. These can be synthesized via using diols rather than alcohols.

Figure: Synthesis of cyclic acetals and cyclic ketals.