Transformation of Sugars into Chiral Polyols over a Heterogeneous Catalyst

Abstract

Transformation of sugars, while maintaining the intrinsic stereochemical structure, is desirable. However, such a transformation requires multistep synthesis with protection and deprotection of the OH groups. Herein, a new method for selective transformation of sugar derivatives into chiral building blocks and a diol 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, without protection of OH groups (except the OH group of the hemiacetal group), over a heterogeneous CeO -supported ReO and Pd (ReO -Pd/CeO ) catalyst by using H as a reducing agent.

Preparation of Highly Active Monometallic Rhenium Catalysts for Selective Synthesis of 1,4‐Butanediol from 1,4‐Anhydroerythritol

“…The Re species are reduced by two electrons, and the reduced Re diolate releases product alkene to form oxidized Re species. The first report on heterogeneous DODH catalysts used carbon‐supported perrhenate, and the development of heterogeneous DODH catalysts has been recently carried out . In particular, we developed ReO x –Au/CeO 2 and ReO x –Pd/CeO 2 as a heterogeneous DODH catalyst and a heterogeneous DODH+hydrogenation catalyst, respectively .…”

“…ReO x –Au/CeO 2 catalyzed the DODH of glycerol to allyl alcohol, erythritol to 1,3‐butadiene, and so on . ReO x ‐Pd/CeO 2 catalyzed the DODH and subsequent hydrogenation of C=C bonds, such as erythritol to 1,2‐ and 1,4‐butanediols (1,2‐ and 1,4‐BuD), methylglycosides with cis ‐OH groups to the corresponding dideoxy products, and so on . Au or Pd promoters have the function of activating H 2 , and the activated hydrogen can move on the CeO 2 surface to enable the reduction of Re species in the reaction .…”

“…The first report on heterogeneous DODH catalysts used carbonsupported perrhenate, [17] and the development of heterogeneous DODH catalysts has been recentlyc arried out. [18][19][20][21][22][23][24][25][26][27][28] In particular,w ed evelopedR eO x -Au/CeO 2 and ReO x -Pd/CeO 2 as a heterogeneous DODH catalyst and ah eterogeneousD ODH + hydrogenation catalyst, respectively. [19][20][21][22][23] Both catalysts ystems use H 2 as the reductant, which is more environmentally benign than other reductantss uch as alcohols.…”

“…[19,20,27] and subsequent hydrogenation of C=Cb onds, such as erythritol to 1,2-and 1,4-butanediols (1,2-and1 ,4-BuD), [22,23] methylglycosides with cis-OH groups to the corresponding dideoxy products,a nd so on. [24] Au or Pd promoters have the function of activating H 2 ,a nd the activated hydrogen can move on the CeO 2 surface to enablet he reduction of Re speciesi nt he reaction. [19][20][21][22][23][24]29] Although Pd is amore effective promoter for H 2 activation,P di sa lso active forC =Ch ydrogenation and thus the product over ReO x -Pd/CeO 2 becomes saturated.…”

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

“…To our knowledge, the current synthetic methods include synthesis from glutamic acid and OsO 4 dihydroxylation of the expensive 4‐penten‐1‐ol or its tosylate . More recently, Tomishige and co‐workers reported the synthesis of enantiopure 125PTO by two‐step reduction of methyl β‐ l ‐arabinopyranoside . Several recent reports have described the synthesis of 125PTO from the furfural platfom (Scheme ).…”