The most effective protecting group for alcohols during a reaction with an electrophilic reagent is the tert-butyldimethylsilyl TBS group. The TBS group is introduced to the alcohol using tert-butyldimethylsilyl chloride TBSCl and a base, typically imidazole.The TBS group is highly effective for several reasons:1. Steric hindrance: The tert-butyl group in the TBS group is bulky, which provides steric hindrance and prevents the electrophilic reagent from reacting with the alcohol.2. Stability: The TBS group forms a stable bond with the oxygen atom of the alcohol, making it less reactive towards electrophilic reagents.3. Selectivity: The TBS group is selective for primary and secondary alcohols, which allows for selective protection of alcohols in the presence of other functional groups.4. Ease of removal: The TBS group can be easily removed after the reaction with electrophilic reagents is complete, using mild conditions such as treatment with a fluoride source like tetra-n-butylammonium fluoride TBAF or hydrofluoric acid HF .Overall, the TBS group provides an effective and selective means of protecting alcohols during reactions with electrophilic reagents, while also being easily removable under mild conditions.