Total synthesis of (+)-brasilenyne. Application of an intramolecular silicon-assisted cross-coupling reaction.
J Am Chem Soc
; 126(39): 12432-40, 2004 Oct 06.
Article
em En
| MEDLINE
| ID: mdl-15453777
The first enantioselective total synthesis of (+)-brasilenyne (1) has been achieved in 19 linear steps, with 5.1% overall yield from l-(S)-malic acid. The construction of the oxonin core containing a 1,3-cis,cis diene unit was accomplished with a tandem ring-closing metathesis/silicon-assisted intramolecular cross-coupling reaction. In addition, a key propargylic stereogenic center was created through a novel, highly diastereoselective ring opening of a 1,3-dioxolanone promoted by TiCl(4). This reaction proceeded through an oxocarbenium ion intermediate and the asymmetric induction was fully controlled by l-malic acid residue. The C(8) stereogenic center was set by a reagent-controlled asymmetric allylboration.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Silício
/
Éteres Cíclicos
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Estados Unidos
País de publicação:
Estados Unidos