Absolute configuration of main chain of AAL-toxins

Article abstract of DOI:10.1016/S0040-4020(01)89343-1

AAL-toxins TA₁ 1 and TA₂ 2, host-specific toxins produced by Alternaria alternata, were degraded to 2-methylbutanol, 3-methylnonan-1,9-diol and N-protected 4-aminobutan-1,3-diol, which were further converted to (R)-MTPA esters. These esters were correlated with synthetic samples by comparison of their 500 MHz ¹H-NMR spectra. The remaining stereocenters were determined by the comparison of ¹H-NMR spectra of 6a and 7 derived from 1 and 2 with those of synthetic model compounds. These data conclude that AAL-toxins possess 2S, 4S, 5R, 11S, 13S, 14R and 15R configurations.