Synthesis of cis-Aryl Cyclopropyl Sulfones

Some new cis-1-(arylsulfonyl)-2-phenylcyclopropanes have been synthesized by the addition of arylthiocarbenes to styrene in presence of excess potassium t-butoxide at low temperatures. The (arylthio)cyclopropanes thus obtained are subsequently oxidized with 30% hydrogen peroxide in acetic acid to corresponding sulfones. The IR and PMR spectra of all these compounds were recorded. Their IR spectra displayed bands in the region 1033–1008 cm−1 which are considered to be the most characteristic of the cyclopropane ring. They have also exhibited bands in the region 850–820 cm−1 characteristic of cis-configuration. The PMR spectra gave complex multiplets in the region 1.4–3.1 ppm. A study of these chemical shifts for ring protons and other substituents reveals that all the substituents tend to cause protons cis-to them to appear at higher fields than those trans-to them. Thus the differences of the chemical shifts can be used as a criterion to distinguish between cis-and trans-1-(arylsulfonyl)-2-phenylcyclopropanes.