Transformation of Sugars into Chiral Polyols over a Heterogeneous Catalyst

Abstract

Transformation of sugars,w hile maintaining the intrinsic stereochemical structure,i sd esirable.H owever,s uch at ransformation requires multistep synthesis with protection and deprotection of the OH groups.Herein, anew method for selective transformation of sugar derivatives into chiral building blocks and ad iol synthon, with retention of the intrinsic configuration (stereo-and regioselectively), is demonstrated. The method is based on the selective recognition of cis-vicinal OH groups in sugars and leads to the one-pot removal of the cis-vicinal OH groups,w ithout protection of OH groups (except the OH group of the hemiacetal group), over aheterogeneous CeO 2 -supported ReO x and Pd (ReO x -Pd/CeO 2 ) catalyst by using H 2 as ar educing agent.

Biorefinery via Achmatowicz Rearrangement: Synthesis of Pentane‐1,2,5‐triol from Furfuryl Alcohol

“…[23] More recently,T omishige and co-workers reported the synthesis of enantiopure 125PTO by two-step reduction of methyl b-l-arabinopyranoside. [24] Several recent reports have described the synthesis of 125PTO from the furfural platfom (Scheme 2). To mishige and co-workers also reported 19 %y ield of 125PTO as as ide product from An ew scalable synthesis of pentane-1,2,5-triol from the furanics platform has been developed.…”

“…Therefore, we used an 80:20 v/v EtOAc/EtOH solventm ixture and were glad to observe significant improvement, affording up to 63 %y ield from 1 (Table 2, entries 20-22) and up to 75 %f rom 2 (Table 2, entries[23][24][25][26]. Furthermore, we observed that in EtOAc/EtOH (80:20 v/v) the temperature had significant effect only on the hydrogenation of 1 (Table 2, entry 20 vs. 21), whereas the hydrogenation of 2 led to similaro utcomes under variousconditions (Table 2, entries[23][24][25][26][27]. 5% Ru/C catalystexhibited superior performance to Pt catalysts and provided up to 98 %y ield directly from 1 at 50 8Ci nE tOH, thus avoiding the use of more complex solventm ixtures (Table 2, entries 28 and 29).…”