Sulfone, methoxymethyl phenyl anions

This general procedure has also been extended to allow for the insertion of a methoxy-containing carbon. The uncat yzed addition of the lithium anion of methoxymethyl phenyl sulfone to ketones proceeds readily at low temperature in dimethoxyethane to form the intermediate adduct. Addition of a Lewis acid (ethylaluminum dichloride or diisobutylaluminum diisopropylamide) directly to the reaction mixture effects the rearrangement reaction to pr uce the ring-expanded a-methoxy ketone. This sequence, illustrated by the example in Scheme 28, is limited to the expansion of four- and five-membered ring ketones. ... 

In a similar vein, the adducts derived from the anion of methoxymethyl phenyl sulfone and cyclic ketones rearrange on Lewis acid catalysis (Scheme 13). This rearrangement is quite stereospecific, in that a single diastereoisomer is formed and it is the most substituted group which migrates. Similar results were obtained with adducts derived from phenyl thiomethyl phenyl sulfone (Scheme 14). ... 

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