Kerner MJ,
Wipf P.
*
University of Pittsburgh, USA
Semipinacol-Type Rearrangements of [3-(Arylsulfonyl)bicyclo[1.1.0]butan-1-yl]alkanols.
Org. Lett. 2021;
23: 3615-3619
DOI:
10.1021/acs.orglett.1c01004
Key words
semipinacol-type rearrangements - spirocycles - synthetic building blocks
Significance
Spirocyclic motifs are often encountered in complex natural products and pharmaceutical compounds. This novel method exploits an acid- or halogen-catalyzed semipinacol rearrangement of (bicyclo[1.1.0]butan-1-yl)alkanols to access spiro[3.4]octanes and related heteroatom-containing spirocycles chemoselectively and in good yield. Synthetic manipulation of the arylsulfone and carbonyl site could give access to an even greater variety of synthetic building blocks.
Comment
The sulfonylbicyclo[1.1.0]butanes used in these transformations are accessed easily and in moderate yield from aryl sulfonyl chlorides. Screening of acidic conditions identified methanesulfonic acid/dichloromethane as the most effective for the semipinacol rearrangement transformation. Although no natural products or pharmaceuticals were prepared, this methodology could be used to readily access complex structures, as shown above.
