Abstract:
Xanthenes are important group of compounds characterized by their
certain biological activities. These compounds can be synthesized from
the corresponding aldehydes. The carbonyl group in aldehydes is one of
the versatile functional groups. Chapter one of this thesis deals basically
with the chemistry of the aldehyde group with especial emphasis on their
reactions as carbanions. This chapter deals also with xanthenes
compounds together with a review of their biological importance, in
addition, a short concise treatment of retrosynthesis analysis was covered.
In this work nine octahydroxanthen-1,8-dione derivatives with their nine
bisdimedone intermediates were designed and synthesized. The total
synthesis was designed from the appropriate disconnections of the target
molecules. Therefore the aldehyde was firstly condensed with dimedone
in order to obtain the bisdimedone derivative, which followed by the
acidic cyclization to form the 9-substituted-1,8-diketo octahydro
xanthenes. The reaction course was followed with TLC technique. All the
intermediates and the final compounds were subjected to UV and IR
analysis. Further more most of the intermediates and the final
octahydroxanthenes were analyzed with 1H and 13C-NMR. The
corresponding hydrazones and oximes were prepared and their m.ps were
recorded.
Possible mechanistic explanation of the different synthetic routes together
with their retrosynthetic analysis were dealt with in chapter three.
The intermediates and the final compounds were scanned for their
antibacterial activity against S. aureus, E. coli and P. aeruginosa, the
compounds were found to possess some antimicrobial activity. The
compounds were assayed for their antifungal activity against C. albicans.
