Chiral Materials from Biomass: 3-deoxy-α-D-ribono-1,4- lactone and 3-deoxy-α-D-arabino-1,4-lactone via the Bromination of Cyrene

The feeding modulator 3-deoxy-D-arabino-1,4-lactone and the diastereomer 3-deoxy-D-ribono-1,4-lactone have been prepared from the biomass pyrolysis product Cyrene (dihydrolevoglucoseone). The arabino-configured lactone was accessed via the diastereoselective bromination of Cyrene, through an enaminebromination/hydrolysis strategy, giving the thermodynamically stable equatorial bromide after a base catalyzed equilibration. A Baeyer-Villiger oxidation and then reaction with benzoate followed by hydrolysis gave the target lactone. 3-Deoxy-D-ribono-1,4-lactone was accessible via the reaction of the bromide with benzoate prior to Baeyer-Villiger reaction resulting in the retention of configuration. The diastereoselectivity for the reactions and the formation of byproducts was rationalized by the involvement of an intermediate oxirane and subsequent House-Meinwald rearrangements.