A study of the epoxidation of 6-deoxyhex-5-enopyranosides. 1,5-Dicarbonyl derivatives and novel synthetic routes to D-xylo-hexos-5-ulose and D-lyxo-hexos-5-ulose

The work described deals with the isolation and characterization of epoxides from 6-deoxyhex-5-enopyranosides and preliminary exploration of their synthetic potential. Prolonged epoxidation reaction times led to their hydrolysis in situ and gave novel protected D-hexos-5-ulose derivatives (sugar 1,5-dicarbonyls). Some reactions of the hexos-5-uloses were studied, and in some cases septanoside (seven-membered-ring saccharide) derivatives were isolated. Novel routes to D-xylo-hexos-5-ulose and D-lyxo-hexos-5-ulose, of interest as intermediates in the synthesis and biosynthesis of inositols and aza sugars, are also described. The structures of the epoxides and novel hexos-5-uloses were established by NMR and X-ray crystallographic methods.     

Novel synthesis of the glycosidase inhibitor deoxymannojirimycin and of a synthetic precursor D-lyxo-hexos-5-ulose

[reaction: see text]. The synthesis of D-lyxo-hexos-5-ulose (5-ketomannose, 1,5-dicarbonyl sugar), a synthetic precursor to the glycoprocessing inhibitor deoxymannojirimycin, was carried out by an in situ epoxidation and hydrolysis of a trimethylsilyl-protected 6-deoxyhex-5-enopyranoside followed by facile removal of the protecting groups. A novel nine-step synthesis of deoxymannojirimycin has also been achieved from methyl alpha-D-mannopyranoside; this involved methanolysis of epoxides derived from an acetylated 1-azido-6-deoxyhex-5-enopyranoside followed by deprotection and catalytic hydrogenation.     

Total synthesis of (+)-mupirocin H from D-glucose

Enantioselective total synthesis of mupirocin H is accomplished starting from D-glucose featuring strategic application of D-glucose derived chirality, diastereoselective Still-Barrish hydroboration, and further elaboration of carbon chain to furnish a phenyltetrazolyl sulfone intermediate, which on coupling with (2S,3S)-2-methyl-3-(triisopropylsilyloxy)butanal under Julia-Kocienski olefination conditions gave an advanced E-olefinic intermediate selectively. The E-olefin was transformed to the 4-hydroxynitrile, a prefinal substrate, which on acid-catalyzed oxidative lactonization furnished the target molecule mupirocin H in 19 steps from known compound 6 (longest linear sequence) with an overall yield of 4.96%.     

A total synthesis of natural cerulenin from D-glucose

$\text{D}$-glucose has served as a chiral synthon in a total synthesis of the fungal metabolite cerulenin.     

Divergent synthesis of two novel muscarine analogues from D-glucose

A divergent synthesis of two new muscarine analogues bearing the (5S)-dioxolanyl isosteric group was achieved starting from d-glucose, enabling access to libraries of potential muscarinic agonists or antagonists. The key step of the synthesis involved a regioselective epoxide ring opening in 2,5:3,4-dianhydro derivatives 5 and 15 with LiAlH₄, whereby the natural stereochemistry of (+)-muscarine (1) and (−)-allo-muscarine (2) was efficiently established.     

Total synthesis of fully acetylated N-acetylneuraminic acid (Neu5Ac), 2-deoxy-beta-Neu5Ac, and 4-epi-2-deoxy-beta-Neu5Ac from D-glucose

Sialic acid and its analogues have been synthesized using a salenCo(II) complex catalyzed hetero Diels-Alder reaction and oxidative azidation (CAN/NaN3) of silyl enol ether as the key steps.     

Stereoselective and efficient total synthesis of optically active tetrodotoxin from D-glucose

A stereoselective and efficient total synthesis of optically active tetrodotoxin (TTX) is described. A polyfunctionalized key cyclitol compound containing branched-chains for the synthesis of TTX was prepared from D-glucose employing the Henry reaction (Nitro aldol reaction) as the key transformation. Stereoselective construction of the alpha-azido-aldehyde branched-chain was achieved via the key spiro alpha-chloroepoxide intermediate.     

A facile and practical synthesis of peracylated 4-thio-D-ribofuranoses from D-glucose

A practical synthesis of a peracylated 4-thio-D-ribofuranose 14 starting from inexpensive d-glucose is described. The C2-C6 portion of D-glucose was utilized, in which sulfur was introduced to C5 in two consecutive displacement reactions with net retention of configuration under mild conditions.     

Total stereospecific synthesis of (+) azimic and (+) carpamic acids from D-glucose

The total synthesis of (+)-azimic and (+)-carpamic acids are described, based on a biomimetic heterocyclization of optically active precursors derived from D-glucose.     

葡萄糖衍生物的手性膦化合物的合成及结构研究

研究葡萄糖吡喃环上同时含有官能团环氧乙烷基和对甲苯磺酸酯时与二苯基膦锂的反应, 一种新的手性膦被得到。它的膦氧化物的晶体结构被测定, 构象为椅式(1C4), 吡喃环上的五个取代基均在直立键上。     

Total synthesis of antibiotic A23187 (calcimycin) from D-glucose

The fully stereocontrolled synthesis of A23187 by using the chirons derived from D-glucose is described.     

An efficient synthesis of D-erythro- and D-threo-sphingosine from D-glucose: olefin cross-metathesis approach

[reaction: see text] The D-erythro- and D-threo-sphingosine were synthesized via E-selective olefin cross-metathesis using a D-glucose-derived building block and long-chain terminal alkene.     

Enantiospecific syntheses of deoxymannojirimycin,fagomine and 2r,5r-dihydroxymethyl-3r,4r-dihydroxypyrrolidine from D-glucose

Methyl 2-azido-3-O-benzyl-2-deoxy-α-D-mannofuranoside (4), readily available from D-glucose, is a common intermediate in the enantiospecific syntheses of deoxymannojirimycin [1,5-dideoxy-1,5-imino-D-mannitol](l), fagomine [1,2,5-trideoxy-1,5-imino-D- arabino hexitol] (2) and 2R,5R-dihydroxymethyl-3R,4R-dihydroxypyrrolidine (3); these syntheses establish the absolute configurations of (2) and (3).     

A synthesis of the marine antibiotic (-)-malyngolide from D-glucose

(-)_Malyngolide, an antibiotic from the marine blue-green alga Lyngbya majuscula, was synthesized in about 30% yield from ethyl 4,6-0-benzylidene-2-deoxy-α-D-erythro-hexopyranosid-3-ulose, a chiral synthon easily derived from commercially available methyl α-D-glucopyranoside.     

Highly stereoselective synthesis of methynolide,the aglycone of the 12-membered ring macrolide methymycin,from D-glucose

A highly stereoselective and efficient synthesis of methynolide, the aglycone of 12-membered macrolide methymycin, was achieved from of C1–C8 and C9–C13 segments synthesized from D-glucose by employing some stereoselective reactions and benzyl-type protecting groups.     

Enantiospecific synthesis of S-quinuclidinol from D-glucose: A strategy for the synthesis of chiral quinuclidines.

Two alternative strategies for the synthesis of quinuclidines from hexoses are outlined. One of these is employed in an enantiospecific synthesis of S-quinuclidinol whereby a two carbon fragment is introduced at C-4 of D-glucose.     

Design and synthesis of cluster neoglycoconjugates based on D-glucose

Synthetic approaches have been developed to tetravalent neoglycoconjugates with different structures of the hydrophobic fragment and D-glucose fragment as branching core. The syntheses have been accomplished by preparation of blocks with terminal C≡C triple bonds and hydrophobic fragment and hydrophilic component (lactose derivative), followed by their conjugation.