Spirocyclic Ketone Construction via Semipinacol-Type Rearrangement

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.

Publikationsverlauf

Artikel online veröffentlicht:
17. Juni 2021