Catalytic enantioselective synthesis of carbocyclic and heterocyclic spiranes via a decarboxylative aldol cyclization† †Electronic supplementary information (ESI) available. CCDC 1999209. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/d0sc02366c

• Published in: Chemical science (Cambridge) Vol. 11; no. 28; pp. 7390 - 7395
• Main Authors: Inanaga, Kazato, Wollenburg, Marco, Bachman, Shoshana, Hafeman, Nicholas J., Stoltz, Brian M.
• Format: Journal Article
• Language: English
• Published: Royal Society of Chemistry 23.06.2020
• Subjects: Chemistry
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d0sc02366c

The synthesis of a variety of enantioenriched 1,3-diketospiranes from the corresponding racemic allyl β-ketoesters via an interrupted asymmetric allylic alkylation is disclosed. The synthesis of a variety of enantioenriched 1,3-diketospiranes from the corresponding racemic allyl β-ketoesters via an interrupted asymmetric allylic alkylation is disclosed. Substrates possessing pendant aldehydes undergo decarboxylative enolate formation in the presence of a chiral Pd catalyst and subsequently participate in an enantio- and diastereoselective, intramolecular aldol reaction to furnish spirocyclic β-hydroxy ketones which may be oxidized to the corresponding enantioenriched diketospiranes. Additionally, this chemistry has been extended to α-allylcarboxy lactam substrates leading to a formal synthesis of the natural product (–)-isonitramine.