Difficult macrocyclizations: new strategies for synthesizing highly strained cyclic tetrapeptides.
Org Lett
; 5(15): 2711-4, 2003 Jul 24.
Article
em En
| MEDLINE
| ID: mdl-12868896
ABSTRACT
[reaction see text] Cyclic tetrapeptides are an intriguing class of natural products. To synthesize highly strained cyclic tetrapeptides we developed a macrocyclization strategy that involves the inclusion of 2-hydroxy-6-nitrobenzyl (HnB) group at the N-terminus and in the "middle" of the sequence. The N-terminal auxiliary performs a ring closure/ring contraction role, and the backbone auxiliary promotes cis amide bonds to facilitate the otherwise difficult ring contraction. Following this route, the all-L cyclic tetrapeptide cyclo-[Tyr-Arg-Phe-Ala] was successfully prepared.
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01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2003
Tipo de documento:
Article