Boekelheide reaction | |
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Named after | Virgil Carl Boekelheide |
Reaction type | Rearrangement reaction |
The Boekelheide reaction is a rearrangement of α-picoline-N-oxides to hydroxymethyl pyridines. It is named after Virgil Boekelheide who first reported it in 1954. [1] Originally the reaction was carried out using acetic anhydride, which typically required a period at reflux (~140 °C). The reaction can be performed using trifluoroacetic anhydride (TFAA), which often allows for a room temperature reaction. [2]
The mechanism of the Boekelheide reaction begins by an acyl transfer from the trifluoroacetic anhydride to the N -oxide oxygen. The α-methyl carbon is then deprotonated by the trifluoroacetate anion. This sets the molecule up for a [3.3]- sigmatropic rearrangement which furnishes the trifluoroacetylated methylpyridine. Hydrolysis of the trifluoroacetate releases the hydroxymethylpyridine.