A convenient, general synthesis of 1,1-dimethylallyl esters as protecting groups for carboxylic acids.
[reaction: see text] Carboxylic acids were converted in high yield to their 1,1-dimethylallyl (DMA) esters in two steps. Palladium-catalyzed deprotection of DMA esters was shown to be compatible with tert-butyl, benzyl, and Fmoc protecting groups, and Fmoc deprotection could be carried out selectively in the presence of DMA esters. DMA esters were also shown to be resistant to nucleophilic attack, suggesting that they will serve as alternatives to tert-butyl esters when acidic deprotection conditions need to be avoided.
Sedighi
Minoo
M
Department of Chemistry and Cancer Center, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, USA.
Lipton
Mark A
MA
D000498:Allyl Compounds / Q000138:chemical synthesis*; D000596:Amino Acids / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D020650:Combinatorial Chemistry Techniques; D004952:Esters; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*
D000498:Allyl Compounds; D000596:Amino Acids; D002264:Carboxylic Acids; D004952:Esters; D010165:Palladium