H. M. R. Hoffmann, J�rgen Rabe
Mar 14, 1984
Citations
0
Influential Citations
66
Citations
Journal
Helvetica Chimica Acta
Abstract
The title dicarboxylic acid 1d has been prepared in 24% overall yield via, 1,4-diazabicyclo[2.2.2]octane (DABCO)-catalyzed coupling of ethanal and tert-butyl propenoate (3) to 4, SN2′-reaction to tert-butyl (Z)-2-romomethyl-2-butenoate (5a), dehydrobrominatin to tert-butyl 2-methylidene-3-butenoate (2c), dimerizatoin to di-tert-butyl 4-vinyl-1-cyclohexene-1,4-dicarboxylate (1c) and acidic ester cleavage. Acidic cleavage of easily obtainable 5a affords (Z)-2-bromomethyl-2-butenoic acid (5a) in 68% yield with respect to ethanal.