SYNTHETIC APPROACHES TO MYCELIANAMIDE

Attempts to synthesize the benzylidene bis-hydroxamic acid system present in mycelianamide (I; R = OH) by direct carbonyl-methylene condensation were unsuccessful. Nycelianamide dimethyl ether (XXIV) is a very unstable substance, which lost one N-methoxyl group as formaldehyde when heated at 77º for 1 hr. Syntheses of compounds closely related to (XXIV) which depended on the introduction of benzylidene unsaturation by slow thermal elimination of CH3SH or CH3SOH at 80-100° consequently gave instead the laotams (XX-XXII) by secondary elimination of formaldehyde. The structural requirements for this elimination of formaldehyde and the stereochemistry of mycelianamide are discussed. © 1968 CSIRO. All rights reserved.