Sulfides, cyclopropyl phenyl reaction with butyllithium

Under the same basic conditions /ra . -l-acetoxymethyl-1-methyl-2-tosylcyclopropane generated an a-sulfonyl anion, which attacked the ester group intramolecularly and afforded 2,5-dimethyl-l-tosyl-3-oxabicyclo[3.1.0]hexan-2-ol (22) in 50% yield.Stereoselective synthesis with a chiral cyclopropyl sulfoxide was experienced when ( )-4-tolylsulfinylcyclopropane was reacted first with butyllithium and then with methyl benzoate and gave 1-benzoyl-1-[(5)-4-tolylsulfinyl]cyclopropane (23a) in 62% yield. A useful reaction took place when 2-(hy-droxymethyl)cyclopropyl phenyl sulfide was treated first with an excess of butyllithium and then with dimethylformamide and gave 2-hydroxy-l-phenylsulfanyl-3-oxabicyclo[3.1.0]hexane (24), a lactol which has been used to carry out various useful synthetic transformations. Another useful reaction occurred when cyclopropyl phenyl sulfones were treated with butyllithium followed by an acyl imidazole to give acyl cyclopropanes in decent yield. 

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