The lithium dianions of crotonic and tiglic acids reacted with n-heptanal, benzaldehyde, isobutyraldehyde, 2, 2-dimethyl-3, 3-dimethoxypropionaldehyde, acetone, and cyclopentanone at-78" C, room temperature, and 65" C to give a-and y-condensation products. The kinetically controlled pathway gives largely or entirely the@ hydroxy acid from condensation at the a-carbon, but at higher temperature the reaction is reversible leading ...
