Studies of the Condensation of Sulfones with Ketones and Aldehydes

The condensation of ketones or aldehydes with sulfones was shown to give a variety of products.
Condensation of 2-methylcyclohexanone with dimethyl sulfone using potassium t-butoxide as base gave
useful yields of 1,2-dimethylenecyclohexane. Under the same conditions, cycloheptanone, 3-methyl-2-butanone, and 2-butanone were converted to dienes. Remarkably, these reaction conditions converted
acetophenone into p-terphenyl (10%) and (E)-1,4-diphenyl-3-penten-1-one (44%). Propiophenone was
converted to 2‘-methyl-p-terphenyl (61%). Using α-tetralone produced 1-methynaphthalene and
naphthalene. No reaction took place with β-tetralone. Using diethyl sulfone with α-tetralone lead to pure
naphthalene. Condensation of isobutyraldehyde and dimethyl sulfone using potassium t-butoxide gave
isoprene in low yield. Using benzaldehyde and benzyl phenyl sulfone in N,N-dimethylacetamide gave
1,2-diphenyl-1-phenylsulfonylethylene, N,N-dimethylcinnamide, and a complex condensation product.
Only 1,2-diphenyl-1-phenylsulfonylethylene was obtained when the solvent was THF.