- Stereoselective reactions. XX. Synthetic studies on optically active β-lactams. III. Stereocontrolled synthesis of chiral intermediate to (+)-thienamycin from D-glucose
-
A chiral key intermediate (19a) for the synthesis of (+)-thienamycin was synthesized starting from D-glucose. The enol ether 13, obtained from the ketone 11 by Horner-Wittig reaction, was transformed to the corresponding methyl ester 16 by pyridinium chlorochromate oxidation or by employing the Wacker process. The ester 16 was further converted to the β-lactam 19a, which is a useful chiral precursor to (+)-thienamycin.
- Ikota,Yoshino,Koga
-
p. 2201 - 2206
(2007/10/02)
-
- HEMISYNTHESE DE NOUVEAUX GLICOSIDES ANALOGUES DE LA DAUNORUBICINE
-
Seven daunorubicin analogs containing α-L-, α-D-, and β-D-glicosidic linkages, in which the natural occuring sugar (L-daunosamine) was replaced by diastereomeric 3-amino-2,3,6-trideoxyhexoses (3-epi-L-daunosamine, D-acosamine, D-daunosamine, D-ristosamine, and 3-epi-D-daunosamine), were prepared.In all cases, glycosidation with daunomycinone was performed in the presence of p-toluenesulfonic acid starting from 1-O-acetyl-2,3,6-trideoxy-4-O-p-nitrobenzoyl-3-trifluoro-acetamidohexopyranoses (prepared from the corresponding methyl 3-amino-2,3,6-trideoxyhexopyranosides) or from 1,5-anhydro-2,3,6-trideoxy-4-O-p-nitrobenzoyl-3-trifluoroacetamidohex-1-enitols (prepared from glycosals or pseudoglycals, the 3-amino group being introduced by substitution with sodium azide and subsequent reduction).Glycosidation was followed by removal of the protecting groups.
- Boivin, Jean,Montagnac, Alain,Monneret, Claude,Pais, Mary
-
p. 223 - 242
(2007/10/02)
-