A practical and flexible de novo synthesis of deoxygenated carbasugars and their cyclitol epoxides

Abstract

Literature on carbasugar and cyclitol epoxide glycomimetics is largely biased towards fully hydroxylated cyclitol structures. Partially deoxygenated sugars of varying configuration are widespread in nature and merit translation into the corresponding carbasugars and cyclitol epoxides as well. For this purpose, we developed a de novo synthesis route comprising enantioselective Brown crotylation and ring-closing metathesis as the key steps and enabling the synthesis of alpha- and beta-carba-paratose, alpha- and beta-carba-colitose as well as four configurational deoxycyclophellitol isosteres in a strategy that allows the synthesis of other configurational isomers.