SYNTHESIS OF ANTIBIOTIC BRANCHED SUGARS

支链糖是植物的重要结构成分

Branched-chain sugars are improtant structural components of many natural substances posessing antibotic and antitumor properties. The objective of the proposed research is to accomplish the de novo chiral synthesis of mycarose, cladinose, arcanose, axenose, pillarose, olivomycose, evermicose, and trioxacarcinose B, utilizing a novel strategy which calls for the construction of the quaternary stereocenters first. As part of this investigation, the chemistry of a -ketoamide dianions (a previously unknown carbaninonic species) will be fully defined. It is anticipated that such information will be of general starategic importance in the planning of future total syntheses of biologically important compounds. Acyclic sterocontrol in secondary allylic alcolhol systems is an important problem in chemical synthesis, and has recently received increasing attention. Results obtained in the proposed research will contribute to the understanding of this process in the more conformationally ambiguous tertiary allylic systems.