Synthesis of polyhydroxy amino acids based on D- and L-alanine from D-glycero-D-gulo-heptono-1,4-lactone.

GÓMEZ, ROMINA VANESA; KOLENDER, ADRIANA ANDREA; VARELA, OSCAR

CARBOHYDRATE RESEARCH

Elsevier Science

Lugar: New York, USA; Año: 2006 vol. 341 p. 1498 - 1504

0008-6215

2-Amino-2,3-dideoxy-D-manno-heptonic acid (7) has been synthesized from 2,5,6,7-teta-O-acetyl-3-deoxy-D-glycero-D-gulo-heptono-1,4-lactone (1), which was readily prepared from D-glycero-D-gulo-heptono-1,4-lactone. O-Deacetylation of 1 followed by treatment with 13:1 (v/v) 2,2-dimethoxypropane-acetone in the presence of p-toluenesulfonic acid gave methyl 3-deoxy-4,5:6,7-di-O-diisopropylidende-D-gluco-heptonate (3) as a crystalline product (80% yield). The free hydroxyl group (OH-2) of 3 was mesylated and substituted by azide to give the corresponding azide derivative 5. Hydrogenolysis and further hydrolysis of the ester function of 5 afforded the a-amino acid 7 (43% overall yield). Compound 7 is an analog of L-alanine having a polyhydroxy chain attached to C-3. The diastereoisomer of 7 at C-2, 2-amino-2,3-dideoxy-D-gluco-heptonic acid (12) was also prepared from 3, by a route that involved the 2,3-dideoxy-2-iodo derivative 8 as a key intermediate.