Stereoselective synthesis of quaternary center bearing azetines and their beta-amino acid derivatives.
J Org Chem
; 73(4): 1264-9, 2008 Feb 15.
Article
en En
| MEDLINE
| ID: mdl-18186644
ABSTRACT
We describe here the use of a stable, four-membered azetine heterocycle for the preparation of highly substituted beta-amino acid derivatives. Imidazolidinone chiral auxiliaries were found to eliminate a competitive reaction pathway that had been present under previously reported conditions for azetine synthesis. The ephedrine derived imidazolidin-2-one 21 was allowed to react as its chlorotitanium enolate with O-methyl or -benzyl oximes under optimized conditions to gain improved access to azetines at the gram scale. The azetines were further found to undergo alkylation with complete diastereocontrol, affording the creation of a quaternary center. Subsequent ring opening with benzoyl chloride and auxiliary cleavage provided the corresponding beta2,2,3-amino carbonyl derivatives in good yields.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Azetinas
/
Aminoácidos
Idioma:
En
Revista:
J Org Chem
Año:
2008
Tipo del documento:
Article
País de afiliación:
Estados Unidos