Syntheses of the fungicide/insecticide allosamidin and a structural isomer

A synthesis of the naturally occurring inhibitor of chitin metabolism, allosamidin 1, involves, as the key step, condensation between the allosamizoline derivative 39, prepared following oxyamination of the cyclopentene 19, and the disaccharide glycosylating agent 54 which was synthesised from 2-acetamido-2-deoxy-D-glucose. The structural isomer 59 of allosamidin is also reported. Brief biological test results obtained using isomers 1 and 59 are recorded.