Synthesis of a new class of aminocyclitol analogues with the conduramine D-2 configuration (original) (raw)

Stereospecific synthesis of a new class of aminocyclitol with the conduramine D-2 configuration

Tetrahedron Letters, 2006

A new aminocyclitol derived from bicyclo[4.2.0 1,6 ]octane was synthesized starting from cyclooctatetraene. Photooxygenation of trans-7,8-diacetoxy-bicyclo[4.2.0]octa-2,4-diene afforded a bicyclic endoperoxide. Reduction of the endoperoxide with thiourea followed by a palladium-catalyzed ionization/cyclization reaction gave an oxazolidinone derivative. Oxidation of the double bond in the oxazolidinone with KMnO 4 followed by acetylation gave the oxazolidinone-tetraacetate whose exact configuration was determined by X-ray diffraction analysis. Hydrolysis of the oxazolidinone ring and removal of the acetate groups furnished the desired aminocyclitol.

Oxazolidinone polycyclitols. Stereospecific synthesis of novel aminocarbasugars with oxazolidinone ring

Tetrahedron, 2012

Two new oxazolidinone polycyclitols, 4,5,7,8,9-pentahydroxy-3-tosyldecahydronaphtho [2,1-d]oxazol-2(9bH)-one and 4,5,6,7,8-pentahydroxy-3-tosyldecahydronaphtho [2,1-d]oxazol-2(9bH)-one were synthesized starting from p-benzoquinone. An endo selective DielseAlder cycloaddition between p-benzoquinone and 1-acetoxybutadiene followed by stereoselective reduction with NaBH 4 eCeCl 3 $7H 2 O led to the formation of an allylic cis-diol. The obtained diols were protected with p-TsNCO to yield biscarbamates and then a palladium-catalyzed ionization/cyclization reaction produced two oxazolidinone derivatives. Oxidation of the two double bonds in either oxazolidinones with OsO 4 followed by acetylation produced oxazolidinone-pentaacetates whose exact configurations were determined by Xray diffraction analysis. Controlled removal of the acetate groups furnished the desired two new oxazolidinone polycyclitols.

Synthesis of Aminocyclitols by Intramolecular Reductive Coupling of Carbohydrate Derived δ- and ε-Functionalized Oxime Ethers Promoted by Tributyltin Hydride or Samarium Diiodide

Journal of Organic Chemistry, 1997

The intramolecular reductive coupling of a series of simple or polyoxygenated oxime ethers δ-or -functionalized with bromide, R, -unsaturated ester, aldehyde, or ketone groups is reported. The cyclization of a nitrile-tethered aldehyde is also studied. These reductive couplings are promoted by tributyltin hydride or samarium diiodide. The reactions proceed under mild conditions, in good chemical yield, and with high stereoselectivity. When applied to highly functionalized substrates derived from carbohydrates, this approach provides a selective entry to enantiomerically pure aminocyclitols of varying regio-and stereochemistry. In particular, the reductive coupling reaction of carbonyl-tethered oxime ethers promoted by samarium diiodide can be performed in a one-pot sequence, following a Swern oxidation step, allowing the direct transformation of hydroxyl-tethered oxime ethers into the corresponding aminocyclitols. Moreover, the resultant O-benzylhydroxylamine products of these cyclizations can be further reduced in situ with excess samarium diiodide, in the presence of water, to the corresponding amino alcohols in excellent yields. Some transformations of these compounds are discussed. Kimura, H.; Uchida, C.; Ohashi, T. J. Chem. Soc., Perkin Trans. 1 1995, 1695, and references cited therein.

Aminocyclopropanes as precursors of endoperoxides with antimalarial activity

Organic & Biomolecular Chemistry, 2010

This contribution describes the synthesis of several novel bicyclic a-amino endoperoxides, including CF 3 -substituted compounds, prepared by the aerobic electrochemical oxidation of a family of bicyclic aminocyclopropanes. These, in turn, are readily synthesised by a titanium-mediated intramolecular cyclopropanation process (Kulinkovich-de Meijere reaction), starting from N-alkenyl amides that contain a vic-disubstituted double bond, with high diastereoselectivity. An evaluation of the biological activities of several of the molecules produced, against the parasite Plasmodium falciparum, is also presented. ; Fax: +33(0)1 6933 5972; Tel: +33(0)1 6933 5979 † Electronic supplementary information (ESI) available: Preparation of the starting amides 3c-j and 3m. Method used for the analysis, by NMR spectroscopy, of the crude products of the intramolecular Kulinkovich-de Meijere reactions, as well as the crude oxidation products obtained from the bicyclic aminocyclopropanes. Fig. 1 Endoperoxides displaying activity against Plasmodium falciparum.

Enzymatic desymmetrisation of conduritol D. preparation of homochiral intermediates for the synthesis of cyclitols and aminocyclitols

Tetrahedron: Asymmetry, 1996

From meso-conduritol D tetraacetate four homochiral partial derivatives, namely (+)-(IR,2R,3S,4S)-1-hydroxy-2,3,4-triacetoxy-5-cyclohexene, prepared through enzymatic reactions catalysed by one of the following lipases: from porcine pancreas, from Mucor mieheJ and from Candida cylindracea. These compounds are of potential utility in the synthesis of cyclitols and aminocyclitols. As an example, the preparation of the previously unreported (+)-conduramine C-4 is also reported.

Synthesis and screening for analgesic and anti-inflammatory activities of some novel amino acid-containing bicyclo compounds

Journal of Young Pharmacists, 2009

Diazabicyclo[4.3.1]decane derivatives are well known opioid receptor ligands, hence, we have developed a novel and simple method for the synthesis of 3, 4-diphenyl-2,5-diaza-bicyclo[4.3.1]deca-1(9),2,4,6(10),7-pentaene-8-carbonyl chloride derivatives containing amino acid moieties. The compounds were structurally conÞ rmed with the help of TLC, IR, NMR, and LCMS spectra. All the title compounds were screened for analgesic activity by using the tail-ß ick method and for anti-inß ammatory activity by using the carrageenan-induced paw edema method using diclofenac sodium as a standard.