Facile acylation of sterically hindered alcohols through ketene intermediates.

[reaction--see text] Carboxylic acids possessing strongly electron withdrawing substituents in the alpha-position in the presence of DCC acylate sterically hindered and chemically sensitive alcohols. The pattern of reactivity, the deuteration experiments, and the formation of a product derived from a [4 + 2] cycloaddition reaction corroborate the existence of ketene intermediates in the reaction.