Common Organic Functional Group Derivatives that Facilitate Work-up, Separation, and Purification

 

The most common functional groups in organic molecules all have some reversible derivatives that exhibit acidic, basic, or heavy metal complexing properties.

 

• The alcohol group can be converted into an O-sulfate that is acidic. 
• The ketone group can be converted into an oxime that is acidic. 
• The carboxylic acid ester can be converted into an acylhydrazide which is milldly  basic and forms stable isolable complexes with heavy metals.

When these common functionalities are present in a reaction starting material but the planned transformation is occurring elsewhere in the molecule replacing alcohol, ketone or ester group respectively with O-sulfate, oxime or acylhydrazide often would make no difference at the reaction site but would facilitate the isolation of product from the subsequent reaction mixture. 

Perhaps the reason it is not done is because the potential interference of these derived functionalities is not so well understood while for the parent functions there is usually many precedents. Another reason is that the ease of work-up, separation, and purification is simply not considered sufficiently important to warrant special facilitation.