the desferrioxamine backbone for example the synthesis can be terminated at the nitrile 7 and this compound reduced to the corresponding tetracoordinate ligand e g by exposing the compound to hydrogen over palladium alternately the octacoordinate ligand can be generated by first reducing the nitrile of the desferrioxamine precursor 9 followed by condensation of the product with a second equivalent of 4 and then by reduction e g with hydrogen over palladium a desamino analog can be prepared beginning with heptanal this aldehyde is treated with the hydrochloride salt of o benzylhydroxylamine 1a and the resulting oxime 2a reduced e g with sodium cyanoborohydride to produce the o benzyl n heptylhydroxylamine 3a in 22 yield the hydroxylamine 3a is next condensed with succinic anhydride to generate the half acid amide 4a in 83 yield this amide is then condensed with amine 8 from the above synthesis the condensation product 6a is finally reduced e g with hydrogen over palladium providing the desamino analog 7a in 86 yield thus it is apparent that the synthetic schemes described above are viable methods for the total synthesis of desferrioxamine b as well as a variety of its homologs and analogs 4 cyanobutanal 1 was prepared from 35 1 g 0 16 mol of the 3 acylthiazolidine 2 thione according to the method of izawa supra the aldehyde was purified by distillation at 83 u00b0 84 u00b0 c 2 mm brown supra to give 9 7 g 61.