Concave reagents, 21: Selective acylations of primary and secondary alcohols by ketenes

Article abstract of DOI:10.1002/jlac.199619961223

Concave pyridines 1 were used to catalyze the addition of primary and secondary alcohols to ketenes 4, and the kinetic data of these catalyses were determined. In inter- and intramolecular competitions the use of 1e-g led to improved selectivities for the acylation of primary alcohols in comparison with secondary alcohols. All primary alcohols react at comparable rates. Observed rate constants were correlated with Taft's E_s values. The starting materials and products were fully characterized. VCH Verlagsgesellschaft mbH, 1996.