Synthesis of stereoregular poly-O-methyl-D- and L-polygalactonamides as nylon 6 analogues.

C. L. ROMERO ZALIZ & O. VARELA

TETRAHEDRON-ASYMMETRY

Elsevier

Lugar: Amsterdam; Año: 2005 vol. 16 p. 97 - 103

0957-4166

Conveniently activated dimers: (pentachlorophenyl 6(6´-tert-butoxycarbonylamino)-6´-deoxy-2´,3´,4´,5´-tetra-O-methyl-D-galactonamide)-6-deoxy-2,3,4,5-tetra-O-methyl-D-galactonate 7 and its analogue in the L- series 16, were prepared respectively from 6-amino-6-deoxy-D- and L-galactonic acid derivatives (5 and 14). Upon release of the amino function of 7 under acidic conditions, polymerization was conducted in a non-polar (CHCl3) or a polar solvent (DMF) affording poly(6-amino-6-deoxy-2,3,4,5-tetra-O-methyl-D-galactonic acid) 11. Similarly, polymerization in DMF from 16 gave the polygalactonamide 18 (L-series). The polyamides were characterized by IR and NMR spectroscopies. The latter technique was also employed for establishing the conformation of 11 in CDCl3 solution. Molecular weights (about 11,000) were estimated by viscosimetry and size exclusion chromatography. Polygalactonamides 11 and 18 were highly hygroscopic and soluble in a variety of organic solvents, including chloroform. The thermal behavior of the polyamides was also studied.