Abstract
We found the interesting results that alkylation of carboxylic acids with methyl iodide using strontium metal proceeded smoothly to afford the corresponding monomethylated ketones, rather than the dimethylated alcohols, preferentially in moderate to good yields. Using the carboxylic acid sodium salt, the yield decreases slightly, but the reaction controls the over–addition of methyla-ting agent to give the dramatically improvement with high selectivities. Next, when benzoic acid reacted with metallic strontium and alkyl iodides, the unexpected reactions occurred to give p–alkylated products of the aromatic ring of benzoic acid in a trace amount. We were interested in the p–allylated product because this allylation reaction is unusual in these conditions and there are only a few reports of the p–alkylation of aromatic carbonyl compounds. As the results of various investigations, the p–alkylated products were obtained predominantly in good yields. Furthermore, it was found that the convenient bulky tert–benzylic alcohol benzoates were prepared by the dialkylation of methyl benzoate with methyl or i–butyl iodide in the presence of metallic strontium, followed by the addition of benzoyl chloride, benzoic anhydride or acetic anhydride as two portions.
