posted on 2020-03-20, 14:51authored byKishor
L. Mendhekar, Tapas R. Pradhan, Debendra K. Mohapatra
Herein,
we report a simple, efficient, highly regioselective, and
broad-scope hydration method that is facilitated by an unusual interception
of an electrophilic intermediate by water generated via acetate group
participation during [3,3]-acyloxy rearrangement. Various carboxylate-directing
groups including acetate, acrylates, pivalates, benzoate or its derivatives,
and those derived from bioactive natural products were successfully
implemented to direct the regioselective hydration for various functionalized δ-acyloxy-β-ketoester
synthesis. The reaction pathway was further confirmed by 18O labeling experiments, and to the best of our knowledge, this is
the first report of hydration through an electrophilic intermediate
generated during [3,3]-acyloxy rearrangement. Synthetic application
includes the synthesis of a modifiable C5-carbon chain, five-, six-,
and seven-membered heterocycles, and natural product diversification.