Asymmetric [4 + 2] Annulation of Cyclobutenones and Pyrazolone 4,5-Diones: Access to Novel δ-Lactone-Fused Spiropyrazolones.
J Org Chem
; 87(8): 5358-5370, 2022 04 15.
Article
em En
| MEDLINE
| ID: mdl-35324180
Although numerous chiral pyrazolones with a six-membered spirocyclic center at the C4 position have been developed, the asymmetric construction of six-membered oxa-spiropyrazolones is still a challenging task in organic synthesis. Herein, we describe the [4 + 2] annulation of cyclobutanones and pyrazoline-4,5-diones for the efficient synthesis of δ-lactone-fused spiropyrazolone derivatives with generally high yields and good enantioselectivities under mild conditions. The successful scale-up synthesis and further transformation of the final product highlight the practicality and reliability of this reaction.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Pirazolonas
/
Lactonas
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article