write the mechanism.

hint think of ring contraction in case of anions

:)

Do you really want the product as the strained 4-membered ring i.e.

in case of sigmatropic Rxn ring contraction does occur

first, acid-base reaction.

then, H+ abstraction.

then, triangular ring formation.

then, attack on carbonyl carbon.

then, 3-memeber ring opens .. hence carbanion formation.

bus..

and this is your favorski rearrangement.

am i correct ??