Conformationally constrained serine analogues: synthesis of new 2-amino-3-hydroxynorbornanecarboxylic acid derivatives.
J Org Chem
; 65(19): 6138-41, 2000 Sep 22.
Article
em En
| MEDLINE
| ID: mdl-10987950
ABSTRACT
A synthesis of the new oxazolone 2, functionalized with the ethoxycarbonyloxy group on methylenic carbon, is presented, starting from 4-hydroxymethylenoxazolone 1 and ethyl chlorocarbonate. Oxazolone 2 was reacted with cyclopentadiene in the presence of EtAlCl(2), giving the two diastereoisomeric cycloadducts exo-3 and endo-3 in a 7030 ratio. Selective hydrolysis of the lactone ring (THF, HCl) gave the corresponding acids 5 and 6 which were transformed into hydroxyacid derivatives 7 and 8, respectively, operating in an ethanolic solution of Me(2)NH. The new 3-hydroxy-2-aminonorbornane-2-carboxylic acids 11 and 12, in which the serine skeleton is included, were obtained by reduction of acids 5 and 6 to derivatives 9 and 10 and a subsequent hydrolysis with HCl.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Serina
/
Norbornanos
Idioma:
En
Ano de publicação:
2000
Tipo de documento:
Article