Alkylation of 2-Oxy-Substituted 1-Sulfonylallyl and 1-Sulfonylvinyl Anions. New Routes to Functionalized Carbocycles and Dihydrofurans

Article abstract of DOI:10.1021/jo00011a021

Alkylation of the anion derived from 2-phenoxy-3-(phenylsulfonyl)-1-propene proceeds α to the phenylsulfonyl group and affords cyclic products from 1,ω-dihalides.Reaction of the monoalkylated products, in which a suitably positioned olefinic or acetylenic unit is present, with sodium benzenesulfinate-acetic acid gives functionalized acetylcyclopentenes and cyclohexenes via C-C bond formation from the allyl cation-sulfinate ion pair.In the vinyl sulfone series, deprotonation of (E)- or (Z)-2-alkoxyvinyl phenyl sulfones rapidly affords the more stable (E)-lithio derivative, an acetaldehyde anion equivalent which reacts normally with aldehydes, ketones, alkyl halides, and epoxides.The latter process may be effected in an intramolecular fashion.Thus, (E)-(2-phenylsulfonyl)vinyl ethers of 2,3-epoxy alcohols cyclize on treatment with amide bases to afford dihydrofurans whose stereochemistry is fully defined by that of the starting epoxy alcohol.