Naphthalene-catalysed Lithiation of 2-(Chlorophenyl)-1,3-dioxolanes: Generation of Formyl- and Acetyl-Phenyllithium Equivalents [1]

The reaction of 2-(chlorophenyl)-1,3-dioxolanes 1 with an excess of lithium powder and a catalytic amount of naphthalene (5 mol %) in the presence of different carbonyl compounds [tBuCHO, Et2CO, (CH2)5CO, PhCOMe] as electrophiles (Barbier-type conditions) in THF at −78°C leads, after hydrolysis with water at the same temperature, to the expected products 3, the corresponding intermediates involved being formyl- or acetyl-phenyl anion equivalents.