[quote="Greedo017"]What would you expect to be the major product formed when 2-pentanone is heated with benzaldehyde at 80 degrees in 5% NaOH solution.

This is an aldol condensation reaction. The NaOH deprotonates one of the alpha hydrogens of the pentanone to form the enolate which then adds via nucleophilc attack to the highly electrophilic benzaldehyde to form the beta hydroxy intermediate which then (at 80 C) dehydrates to form the alph/beta ubnsaturated product (a substituted styrene big ugly iupac name which i am too lazy to look up). The tricky part of this is which alpha hydrogen gets deprotonated as there are three on the methyl of the pentanone and 2 on the alpha methylene. My guess is it is the kinetic product (due to the vigorous conditions) so the proton would e predominately from the methyl group. Am I right? Greed?