Mannaro-1,4:6,3-dilactone

Varela et al. described some stereoregular hydroxylated polymannaramides [94] by the reaction of o-mannaro-1,4 6,3-dilactone with even-numbered alkylenediamines (n = 2, 6, 8, 10, 12). Hydroxylated stereoregular and non-stereoregular polyamides were also prepared by the same authors [95] from hexamethylene diamine and pentachlorophenyl (2S)-5-oxo-2-tetrahydrofurancarboxylate, synthesized [96] from the chiral (25)-2-hydroxypentane-dioic acid 5,2-lactone. The latter was obtained [97] by deamination of the easily available L-glutamic acid. 

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