A short total synthesis of natural carbasugars

Abstract

(-)-Quinic acid was utilized for the synthesis of natural carbasugar isolated from Streptomyces lincolnensis, which is known to produce antibiotics and metabolites of the lincomycin group. Quinic acid is a cheap material readily available from glucose fermentation. Biomass-derived molecules, especially polyols, are interesting starting materials containing several stereochemically defined functional groups. Hemisynthesis and use of biomass-derived chiral molecules as starting materials of asymmetric synthesis responds to current financial, and most importantly, environmental demands. <br/>Hemisynthesis enables to perform short and efficient syntheses without complexity to build up chiral centers, especially in the case of small highly functionalized molecules. In previous 12-step total synthesis of target carbasugar, the cyclohexane scaffold was achieved in 8 steps with the help of kinetic enzymatic resolution. With our hemisynthetic pathway, we can reduce the amount of synthetic steps to 3-5. In addition to a short total synthesis of carbasugars, our methodology may be adapted to build up polyol subunits of other biologically active natural products.