Formyl chloride amine-protecting group

The acyl derivatives are formed very easily (usually by reaction of the amine with the acyl chloride or anhydride, employing the Schotten-Baumann procedure ) and a good number of them have been used to protect various amines. While all of them can be removed with varying degrees of ease, using acidic or basic hydrolysis, some protecting groups can be removed by other means such as oxidation (formyl, phlorethyl), reduction (formyl, dibenzylphosphonyl) or electrolysis (phloretyl, benzoyl). 

The formyl group in 13 was used to construct the piperidine A ring. Thus, once 13 was converted into an O-benzyl oxime, a hydroboration— oxidation reaction led to alcohol 14. Protection of the hydroxy group withp-methoxybenzyl chloride also caused the eHmination of the O-benzyl oxime moiety to give a nitrile, which was then reduced to the primary amine 15. 

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