1-Deoxy-d-xylulose:  Synthesis Based on Molybdate-Catalyzed Rearrangement of a Branched-Chain Aldotetrose

Abstract

1-Deoxy-D-xylulose has been prepared in seven steps and approximately 21% overall yield from 2,3-O-isopropylidene-D-erythrono-1,4-lactone. The key reaction involves transformation of a branched-chain aldotetrose to the 1-deoxy-2-ketopentose catalyzed by molybdic acid. Other branched-chain aldotetroses containing bulkier substituents at C2 also engage in the conversion, suggesting routes to protected 2-ketoses and alpha-ketoacids/esters. This synthetic route mimics reactions of the non-mevalonate isoprenoid pathway in plants and bacteria. [reaction: see text]

Sn-Beta zeolites with borate salts catalyse the epimerization of carbohydrates via an intramolecular carbon shift

“…A rare exception to this mechanism was discovered by Bílik, who showed that treatment with catalytic amounts of molybdic acid under acidic conditions will epimerize aldoses via transition states that promote a 1,2 carbon shift28. Many catalytic systems based on molybdate chemistry have been investigated2930. The accepted mechanism involves the complex formation of a binuclear molybdate species with four adjacent hydroxyl groups (OH-1 to OH-4) in the sugar3132.…”

Preparation of Isotope Labeled/Unlabeled Key Intermediates in 2‐Methyl‐D‐erythritol 4‐Phosphate Terpenoid Biosynthetic Pathway

“…In the route developed by Serianni and co-workers [16], 11 was prepared in seven steps in a 21% overall yield from commercial 2,3-O-isopropylidene-d-erythrono-1,4lactone 59 (Scheme 12). NaBH 4 Reduction of 59 in H 2 O gave sugar 60, which was successively alkylated with CH 2 O to 61, and then methyl-glycosidated to afford bfuranoside 62.…”

Reduction of sugar lactones to hemiacetals with lithium triethylborohydride

“…1, 2 The commonly used reagents for this transformation include NaBH 4, 3, 4 and organic-soluble metal hydrides. 2, 5, 6 LiAlH 4 under controlled reaction conditions has also been used for this purpose.…”