A short total synthesis of natural carbasugars

(-)-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.
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.