- A latent reactive handle for functionalising heparin-like and LMWH deca- and dodecasaccharides
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d-Glucosamine derivatives bearing latent O4 functionality provide modified H/HS-type disaccharide donors for a final stage capping approach enabling introduction of conjugation-suitable, non-reducing terminal functionality to biologically important glycosaminoglycan oligosaccharides. Application to the synthesis of the first O4-terminus modified synthetic LMWH decasaccharide and an HS-like dodecasaccharide is reported.
- Miller, Gavin J.,Broberg, Karl. R.,Rudd, Claire,Helliwell, Madeleine R.,Jayson, Gordon C.,Gardiner, John M.
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p. 11208 - 11219
(2015/11/27)
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- Synthesis of N-oxyamide-linked neoglycolipids
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N-Oxyamide-containing compounds have shown improved metabolic stability and interesting secondary structures due to the good hydrogen bond-donating property of N-oxyamide. β-Glucolipids linked by the N-oxyamide bond have been successfully synthesized as novel mimics of glycoglycerolipids and glycosphingolipids.
- Chen, Na,Xie, Juan
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p. 10716 - 10721
(2015/02/19)
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- A NOVEL PROCESS FOR MAKING ALISKIREN, ITS NOVEL INTERMEDIATES AND CERTAIN NOVEL COMPOUNDS
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A novel process for making Renin inhibitors like Aliskiren is disclosed. Its novel intermediate compounds and method of making them are also disclosed.
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- Zeolite catalyzed selective deprotection of di- and tri-O-isopropylidene sugar acetals
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H-Beta zeolite, a microporous solid acid, is demonstrated to be an efficient catalyst for the selective deprotection of cyclic as well as acyclic O-isopropylidene sugar acetals derived from d-glucose, d-xylose, d-mannose, and d-mannitol in aqueous MeOH at room temperature. A notable observation is the conversion of d-mannitol triacetonide into 1,2:3,4-di-O-isopropylidene-d-mannitol (48%) and 3,4-O-isopropylidene-d-mannitol (36%) brought about in 6 h by H-beta zeolite and the non-occurrence of any hydrolysis in the case of H-ZSM-5 catalyzed reaction in 24 h under the same conditions.
- Bhaskar, Pallooru Muni,Mathiselvam, Manoharan,Loganathan, Duraikkannu
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p. 1801 - 1807
(2008/12/21)
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- Bifunctional acyclic nucleoside phosphonates: synthesis of chiral 9-{3-hydroxy[1,4-bis(phosphonomethoxy)]butan-2-yl} derivatives of purines
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We report herein a general method for the synthesis of new types of chiral acyclic nucleoside four-carbon bisphosphonates. The alkylation of 2-amino-6-chloropurine and adenine was performed with (2S,3S)- or (2R,3R)-1,4-[bis(diisopropoxyphosphoryl)methoxy]]-3-[(methylsulfonyl)oxy]butan-2-yl benzoate. Alkylations provided (2R,3R) or (2S,3S) N9-substituted nucleobases, which were further converted to other derivatives. These conversions included either a modification of the nucleobase or transformation of the bisphosphonate chain. Subsequent deprotection of the diisopropyl esters with bromotrimethylsilane provided the resulting (2R,3R)- or (2S,3S)-bisphosphonic acids.
- Vrbkova, Silvie,Dracinsky, Martin,Holy, Antonin
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p. 2233 - 2247
(2008/02/11)
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- An efficient, one-pot synthesis of fosfomycin dialkyl esters from (R)-2-tosyloxypropanal
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(R)-2-Tosyloxypropanal (4) was prepared from D-mannitol in a 7-step sequence (51% overall yield). Addition of dialkyl phosphonates to 4 in the presence of titanium isopropoxide and the subsequent treatment with DBU stereoselectively afforded, in one-pot, fosfomycin dimethyl (5a) and dibenzyl (5b) esters both in 58% isolated yield.
- Hanaya, Tadashi,Nakamura, Yuichi,Yamamoto, Hiroshi
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p. 983 - 989
(2008/09/19)
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- Synthesis and DNA-binding ability of pyrrolo[2,1-c][1,4]benzodiazepine- azepane conjugates
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A series of pyrrolobenzodiazepine-azepane conjugates linked through different alkane spacers have been prepared and their DNA thermal denaturation studies have been carried out. One of the compound (4b), elevates the DNA helix melting temperature of the CT-DNA by 2.0°C after incubation for 36 h at 37°C.
- Kamal, Ahmed,Reddy, D. Rajasekhar,Reddy, P. S. Murali Mohan,Rajendar
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p. 1160 - 1163
(2007/10/03)
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- Asymmetric catalysis based on chiral phospholanes and hydroxyl phospholanes
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Chiral phosphine ligands derived from chiral natural products including D-mannitol and tartaric acid. The ligands contain one or more 5-membered phospholane rings with multiple chiral centers, and provide high stereoselectivity in asymmetric reactions.
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Page column 14-15
(2010/02/06)
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- A Novel Chiral Ferrocenyl Phosphine Ligand from Sugar: Applications in Rh-Catalyzed Asymmetric Hydrogenation Reactions
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(Matrix Presented) A new chiral ferrocenyl diphosphine ligand 3 was synthesized from readily available D-mannitol. Rh-complex with this ligand showed high enantioselectivity and reactivity in the asymmetric hydrogenation of dehydroamino acid derivatives and itaconic acid derivatives. Up to over 99% ee and 10 000 TON were achieved with this catalytic system.
- Liu, Duan,Li, Wenge,Zhang, Xumu
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p. 4471 - 4474
(2007/10/03)
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- Asymmetric catalysis based on chiral phospholanes and hydroxyl phospholanes
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Chiral phosphine ligands derived from chiral natural products including D-mannitol and tartaric acid. The ligands contain one or more 5-membered phospholane rings with multiple chiral centers, and provide high stereoselectivity in asymmetric reactions.
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Page column 14-15
(2010/01/30)
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- Polyhydroxylated azepanes as new motifs for DNA minor groove binding agents
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The synthesis of 1,3-bis-[3,4,5,6-tetrahydroxyazepane-N-p-phenoxy] and 1,3-bis-[3,4,5,6-tetrahydroxyazepane-N-p-benzyloxy] propanes is reported. These compounds have been prepared to investigate the potential of incorporating iminosugars as useful recognition elements in DNA minor groove binding agents. The compounds were shown to have very moderate binding affinities for DNA in thermal denaturation and ethidium bromide displacement assays when compared with propamidine. They were also found to possess some in vitro anticancer activity that did not correlate with their DNA binding affinity.
- Johnson, Heather A.,Thomas, Neil R.
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p. 237 - 241
(2007/10/03)
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- D-mannitol derivatives as HIV aspartyl protease inhibitors
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A D-mannitol derivative selected from the group consisting of a compound of formula pharmaceutically acceptable derivatives thereof and where applicable or appropriate pharmaceutically acceptable salts thereof, wherein R1, R2, R3and R4are the same or different and may each independently be selected from among alkyl and aryl (i.e. aromatic including aromatic like) groups. The D-mannitol derivatives may be used as HIV aspartyl protease inhibitors.
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- An efficient and selective method for hydrolysis of acetonides
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Acetonide was selectively and efficiently cleaved with cerium (III) chloride heptahydrate and oxalic acid in acetonitrile. This method was found to be of good functionalities compatibility with such acid sensitive groups as Tr, PMB, TBDMS, TBDPS, OAc, OBz, OTs, OTf.
- Xiao,Bai
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p. 535 - 537
(2007/10/03)
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- Highly Flexible Synthetic Routes to Functionalized Phospholanes from Carbohydrates
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Highly functionalized phospholanes 15, 17, and 26 and the corresponding diastereomers in which the configurations of the phospholane carbon-2 and carbon-5 are inverted can be readily prepared from D-mannitol by displacement of the appropriate dimesylate or cyclic sulfate with dilithium-phosphide reagents. The diols from which these ligands are prepared can also be converted into diarylphosphinite ligands. A route to related monophosphines bearing hemilabile tert-butylthio groups is also described. Complexes of these ligands and of related deprotected derivatives are potentially useful for enantioselective catalysis in organic and aqueous media.
- Yan, Yuan-Yong,RajanBabu
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p. 900 - 906
(2007/10/03)
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- Synthesis of chiral hydroxyl phospholanes from D-mannitol and their use in asymmetric catalytic reactions
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Chiral hydroxyl monophosphane 3 [(2S,3S,4S,5S)-3,4-dihydroxy-2,5-dimethyl-1-phenylphospholane] and bisphospholanes 5a [1,2-bis[(2S,3S,4S,5S)-3,4-dihydroxy-2,5-dimethylphospholanyl]benzene] and 5b [1,2-bis[(2S,3S,4S,5S)-2,5-diethyl-3,4-dihydroxyphospholanyl]benzene] were synthesized from readily available D-mannitol in high yields. Strategies for protection and deprotection of OH-groups in the presence of phosphines have been explored. Rate acceleration in the Baylis - Hillman reaction was observed when a hydroxyl phosphine was used as the catalyst. Rhodium complexes with chiral bisphospholanes are highly enantioselective catalysts for the asymmetric hydrogenation of various kinds of functionalized olefins such as dehydroamino acid derivatives, itaconic acid derivatives, and enamides. An interesting feature of the hydroxyl phospholane system is that hydrogenation of some substrates can be carried out in water with >99% ee and 100% conversion (e.g., itaconic acid).
- Li, Wenge,Zhang, Zhaoguo,Xiao, Dengming,Zhang, Xumu
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p. 3489 - 3496
(2007/10/03)
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- Rhodium-hydroxyl bisphospholane catalyzed highly enantioselective hydrogenation of dehydroamino acids and esters
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A chiral hydroxyl bisphospholane, 1,2-bis[(2S,3S,4S,5S)-3,4-dihydroxyl-2,5-dimethylphospholanyl]benzene (4), was synthesized from readily available D-mannitol. Its Rh(I) complex catalyzes asymmetric hydrogenation of dehydroamino acids and their ester derivatives with excellent enantioselectivities (98 to >99% ee).
- Li, Wenge,Zhang, Zhaoguo,Xiao, Dengming,Zhang, Xumu
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p. 6701 - 6704
(2007/10/03)
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- Diastereoselective Grignard Additions to O-Protected Polyhydroxylated Ketones: A Reaction Controlled by Groundstate Conformation?
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The O-protected polyhydroxy ketones 9-14 and 39, 42 add σ-type Grignard reagents with >90:10 stereoselectivity to give the 3,4-syn-adducts 17-22 and 43, 45, respectively, as the major diastereomers (Tables 1 and 2). The stereoselectivity is interpreted in terms of early transition states which are very close to the groundstate conformations shown in Figure 6 and 7. These demonstrate that the "top face" of the carbonyl group is much less shielded than the "bottom" face, Complexation phenomena are of minor importance. It is also shown that the classical transition state models (Felkin-Anh or chelate Cram) are not applicable to polyoxygenated ketones.
- Mulzer, Johann,Pietschmann, Catarina,Buschmann, Jürgen,Luger, Peter
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p. 3938 - 3943
(2007/10/03)
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- Studies on polyether natural products: Asymmetric synthesis of bis(tetrahydrofuran)
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Synthesis of the bis(tetrahydrofuran) moiety present in polyether natural products has been carried out by involving the asymmetric synthesis and chiron approach.
- Rao, A. V. Rama,Reddy, K. L. N.,Reddy, K. Ashok
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p. 1203 - 1208
(2007/10/02)
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- Stereocontrolled synthesis of HIV-1 protease inhibitors with C2-axis of symmetry
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An efficient and stereocontrolled synthesis of various C2-symmetric HIV-1 protease inhibitors is described, starting from commercially available and inexpensive D-mannitol.
- Ghosh, Arun K.,McKee, Scan P.,Thompson, Wayne J.
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p. 5729 - 5732
(2007/10/02)
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- Process for selective halogenation of primary hydroxyl groups
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Epoxy compounds for use as epoxy resins are prepared from relatively inexpensive and renewable resources via a selective halogenation process. Primary pendant hydroxyl groups on straight carbon chain compounds with oxygen atoms pendant to each carbon are selectively halogenated with, for example, carbon tetrachloride. A scavenger agent, triphenylphosphine and pyridine, is used to complex the residual portion of reacted halogenating agent. One additional step with the halogenated intermediate yields epoxy compounds which, when cured, yield epoxy resins.
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- SYNTHESIS OF DIEPOXIDES AND DIAZIRIDINES, PRECURSORS OF ENANTIOMERICALLY PURE α-HYDROXY AND α-AMINO ALDEHYDES OR ACIDS, FROM D-MANNITOL
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Specific activations or protections of the hydroxyl groups of 3-4-O-isopropylidene-D-mannitol 2 followed by intramolecular SN2 reactions, lead to the chiral diepoxides 4 and 7 and to the chiral diaziridines 9 and 13 precursors of enantiomerically pure α-hydroxy and α-amino aldehydes or acids.
- Merrer, Yves Le,Dureault, Annie,Greck, Christine,Micas-Languin, Dominique,Gravier, Christine,Depezay, Jean-Claude
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p. 541 - 548
(2007/10/02)
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- THE SYNTHESIS OF 1,2:5,6-DI-O-ISOPROPYLIDENE-D-MANNITOL: A COMPARATIVE STUDY
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Three different methods of acetonation of D-mannitol using (a) acetone and zinc chloride, (b) 2,2-dimethoxypropane, 1,2-dimethoxyethane, and tin(II)chloride, and (c) 2-methoxypropane, N,N-dimethylformamide, and p-toluenesulfonic acid were studied in detail and compared, using gas-liquid chromatographic techniques.In each reaction, isomeric diacetals are formed, but method a gives the 1,2:5,6-diacetal in the highest yield (63percent).Methods b and c give a more complex mixture of acetals than proposed in the literature, and both methods are less economical than a.A new 1,2:3,6:4,5-tri-O-isopropylidene-D-mannitol could be separated, and its graded hydrolysis was compared to that of the 1,2:3,4:5,6-triacetal.
- Kuszmann, Janos,Tomori, Eva,Meerwald, Ingrid
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- STEREOSPECIFIC SYNTHESIS OF ISOMERIC 4-SUBSTITUTED 9-(2,3-DIHYDROXYBUTYL)ADENINES
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Reduction of ethyl 2,3-O-isopropylidene-D-tartrate with sodium borohydride afforded (4S,5S)-2,2-dimethyl-1,3-dioxolane-4,5-dimethanol (Va) which was benzoylated to give monobenzoyl derivative Vd and further transformed into p-toluenesulfonyl derivative Ve.Reaction of the compound Ve with sodium salt of adenine followed by methanolysis gave 2,3-O-isopropylidene derivative Vf which on acid hydrolysis afforded 9-(2S,3S)-(2,3,4-trihydroxybutyl)adenine (Ia).The enantiomer IIa was obtained from 3,4-O-isopropylidene-D-mannitol via (4R,5R)-2,2-dimethyl-1,3-dioxolane-4,5-dimethanol (VIa) using the same procedure.Reaction of compounds Vf and VIf with p-toluenesulfonyl chloride afforded 4-O-p-toluenesulfonyl derivatives Vg and VIg.These compounds were also obtained from Va and VIa via di-p-toluenesulfonyl derivatives Vc and VIc by reaction with sodium salt of adenine.Treatment of compounds Vg and VIg with sodium iodide gave 4-iodo derivatives Vh and VIh which on reaction with tri-n-butyltin hydride, followed by acid hydrolysis, afforded enantiomeric threo-2,3-dihydroxybutyl derivatives Ib and IIb.Compounds Vg and VIg on treatment with sodium azide, subsequent catalytic hydrogenation of the intermediates Vj and VIj and acid hydrolysis afforded enantiomeric threo-9-(4-amino-2,3-dihydroxybutyl)adenines (Ic, IIc).Reaction of methyl threo-3-phenylglycerate (VIIb) with acetone, followed by reduction with lithium aluminum hydride, gave 2,2-dimethyl-4-phenyl-1,3-dioxolane-5-methanol (VIIIb) which was converted by reaction with p-toluenesulfonyl chloride, condensation with sodium salt of adenine and acid hydrolysis into 9-(RS)-threo-(3-phenyl-2,3-dihydroxypropyl)adenine (I, IId).Methyl ester of D-eritadenine (IXb) was transformed into 2,3-O-isopropylidene derivative XIa which on reduction with sodium borohydride afforded the alcohol XIb.Its acid hydrolysis gave 9-(2R,3S)-erythro-(2,3,4-trihydroxybutyl)adenine (IIIa); tosylation of compound XIb, successive treatment with sodium iodide and tri-n-butyltin hydride and acid hydrolysis afforded 9-(2R,3S)-erythro-(2,3-dihydroxybutyl)adenine (IIIb).The enantiomers IVa and IVb were obtained analogously from L-eritadenine.The racemic derivative Ib + IIb was prepared from (RS)-threo-2,3-dihydroxybutyric acid via p-toluenesulfonyl derivative of racemic 2,2,4-trimethyl-1,3-dioxolane-5-methanol (IIIc) by reaction of sodium salt of adenine followed by acid hydrolysis.
- HOLY, Antonin
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p. 173 - 189
(2007/10/02)
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- REINVESTIGATION OF THE ACETALATION OF D-GLUCITOL WITH ACETONE-ZINC CHLORIDE
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The acetonation of D-glucitol in the presence of zinc chloride has been studied in detail by gas-liquid chromatographic techniques.From among the 12 different peaks, those belonging to the 1,2:3,4:5,6-tri-, 1,2:3,5:4,6-tri-, 3,4:5,6-di-, 2,3:5,6-di-, 1,2:3,4-di-, 1,2:5,6-di-, 1,2:4,6-di-, 1,2-mono-, 2,3-mono-, 3,4-mono-, and 5,6-mono-acetals could be identified.The course of the reaction was also studied by g.l.c.From the time dependent ratio of the different acetals, it could be concluded that the reaction is kinetically controlled at the beginning, when terminal acetals are mainly formed.In the thermodinamically controlled equilibrium, reached after 5 days, the 1,2:3,4:5,6-tri- and the 2,3:5,6-di-acetal are present in almost equal proportions.The structure of the (new) 1,2:3,5:4,6-triacetal was established by mass-spectrometric and 13C-n.m.r. investigation.
- Kuszmann, Janos,Sohar, Pal,Horvath, Gyula,Tomori, Eva,Idei, Miklos
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p. 243 - 254
(2007/10/02)
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