Rational synthesis of contra-thermodynamic spiroacetals by reductive cyclizations.
J Am Chem Soc
; 127(2): 528-9, 2005 Jan 19.
Article
em En
| MEDLINE
| ID: mdl-15643869
ABSTRACT
A synthesis of spiroacetals was developed using a reductive cyclization strategy that leads stereoselectively to spiroacetals with a single anomeric stabilization. The method begins with the synthesis of spiro ortho esters. The ortho ester is converted to a cyano acetal. Reductive lithiation of the cyano acetal generates an axial dialkoxylithium reagent, and intramolecular cyclization produces a new ring with retention of configuration. The strategy is convergent and produces complex spiro acetals in only a few steps. The method will be useful in the synthesis of natural products and will facilitate the synthesis of previously inaccessible contra-thermodynamic acetals.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos de Espiro
/
Acetais
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2005
Tipo de documento:
Article