Propiophenone solid support

One of the most general approaches to the synthesis of this type of compounds involves the Lewis acid promoted rearrangement of acetals of a-substituted propiophenones [4,5]. Besides silver salts, a large variety of soft and borderline Lewis acids have been found to be convenient catalysts for the 1,2-aryl shift, noticeably zinc halides in substoichiometric amounts [6]. As final products need to be free of metal traces for human consume, the use of Lewis acids supported on microporous solids can be advantageous since a better recovering of the catalyst can be anticipated. 

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