Naphthalene-catalysed lithiation of 2-(chlorophenyl)-1,3-dioxolanes: Generation of formyl- and acetyl-phenyllithium equivalents [1]

The reaction of 2-(chlorophenyl)-l,3-dioxolanes 1 with an excess of lithium powder and a catalytic amount of naphthalene (5 mol %) in the presence of different carbonyl compounds [(BuCHO)-Bu-t, Et2CO, (CH2)(5)CO, PhCOMe] as e lectrophiles (Barbier-type conditions) in THF at -78 degrees C leads, after hydrolysis with water at the same temperature, to the expected products 3, the corresponding intermediates involved being formyl- or acetyl phenyl an ion equivalents, (C) 1999 Elsevier Science Ltd. All rights reserved.