Semipinacol-Type Rearrangements of [3-(Arylsulfonyl)bicyclo[1.1.0]butan-1-yl]alkanols.
Michael J KernerPeter WipfPublished in: Organic letters (2021)
Selective lithiation of arylsulfonylbicyclo[1.1.0]butanes at the bridgehead methine and addition to carbonyl compounds yield tertiary bicyclobutyl alcohols that form spiro[3.4]octanes and related heteroatom-containing spirocycles via an acid- or halogen-mediated semipinacol rearrangement. Further synthetic transformations at the carbonyl or arylsulfone positions, in general in high yield and good chemoselectivity, allow access to acetals, difluorides, amides, and methylenecyclobutene building blocks.
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