27
Jan
Acetals And Ketals As Protecting Groups. Acetals are among the most com-monly used protecting groups for aldehydes and ketones. Second do some reaction on another part of our moleculethat would have been incompatible with the carbonyl group. These functions are removed under acidic conditions. The chemical disguise used with group B is called a protecting group or protective group.
Acetals and ketals are readily deprotected under neutral conditions in the presence of acetone and indiumIII trifluoromethanesulfonate as catalyst at room temperature or mild microwave heating conditions to give the corresponding aldehydes and ketones in good to excellent yields. They can be used for example when a selective reduction of an ester is needed in the presence of an aldehyde or a ketone. Acetals as protecting groups and thioacetals. Cyclic acetals and ketals are the most useful carbonyl aldehyde or ketone protecting groups. Second do some reaction on another part of our moleculethat would have been incompatible with the carbonyl group. An undergraduate or graduate student in Chemistry may indeed carry out the above reaction in a round bottom flask using Methanol as the solvent in order to convert an aldehyde to an acetal as part of a Protecting Group strategy.
In the present study protecting groups of moderate stability such as acetals and ketals were investigated as pendant blocking groups in polyvinyl phenols.
Acetals and Ketals as Protecting Groups So what we have is a reaction that we can use to. Acetals and Ketals as Protecting Groups So what we have is a reaction that we can use to. Acetals and ketals are excellent protecting groups for aldehydes and ketones. For example suppose you wish to prepare the following alcohol from a β-ketoester. Ketals as protecting group Cyclic carbonates and cyclic boronates have also found considerable use as protective groupsIn contrast to most acetals and ketals the carbonates are cleaved with strong base and sterically unencumbered boronates are readily cleaved by water. Acetals as Protecting Groups for Aldehydes and Ketones Acetals are the protecting groups for aldehydes and ketones.