Sterically Deactivated and Base-labile Alcohols

Alcohols can be converted into esters under both acidic or basic reaction conditions, and numerous methods have been developed which will be suitable for most alcohols. Problems can, however, arise if the alcohol is sterically hindered. Strongly acidic alcohols or phenols can usually be readily converted into esters [45], but these will be reactive acylating reagents themselves, and may be hydrolyzed during aqueous work-up. (This can sometimes be avoided by performing the work-up with CH2C12/H20.) 

1 Schlecker, R. Seebach, D. Lubosch, W. CH-Aciditat in a-Stellung zum N-Atom in N,N-Dialkylamiden mit sterisch geschiitzter Carbo-nylgruppe zur nucleophilen Aminoalkylie-rung. Helv. Chim. Acta 1978, 61, 512-526. 

2 Bengtsson, S. Hoberg, T. Pivaloyl-directed regioselective synthesis of 2,3,6-trioxygenated benzamides phenolic metabolites of remoxi-pride./. Org. Chcm. 1993, 58, 3538-3542. 

Sugimoto, H. Doda, K. Maruoka, K. Esterification of carboxylic acids catalyzed by in situ generated tetraalkylammonium fluorides. Tetrahedron Lett. 2001, 42, 9245—9248. 

4 Shieh, W.-C. Dell, S. Repic, O. Nucleophilic catalysis with DBU for the esterification of carboxylic acids with dimethyl carbonate. J. Org. Chem. 2002, 67, 2188-2191. 

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