Secosulfenylation cyclobutanones

Trost also found that treatment of these cyclobutanones with sodium methoxide and diphenyl disulfide leads to in situ bisulfenylation and ring cleavage (secosulfenylation). This was applied to the total synthesis of verrucarol, a complex tetrahydrochromanone substituted at the ring junction by a hydroxymethyl substituent. The synthetic strategy twice used the cyclobutanone formation from 1-lithiocyclo-propyl phenyl sulfide and a ketone, followed by the secosulfenylation process and Baeyer-Villiger type rearrangement of cyclobutanone. Only this part of the synthesis is described in Scheme 28. 

SecosulfenylatioH. Treatment of a cyclobutanone with diphenyl disulfide (excess) in methanol containing sodium methoxide (excess) results in slow bissulfenylation and ring cleavage (equation I). This secosulfenylation is an... 

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