- Synthesis of both enantiomers of conduritol C tetraacetate and of meso-conduritol D tetraacetate by oxidation of benzoquinone bis(ethylene acetal)
-
Epoxidation of p-benzoquinone bis(ethylene acetal) (1) with m-chloroperbenzoic acid or hydrogen peroxide/benzonitrile afforded corresponding monoepoxide 2, which was converted into p-benzoquinone mono(ethylene acetal) monoepoxide 5 with perchloric acid. D
- Lang, Martin,Ziegler, Thomas
-
p. 768 - 776
(2008/02/07)
-
- Stereoselective synthesis of myo-, neo-, L-chiro, D-chiro, allo-, scyllo-, and epi-inositol systems via conduritols prepared from p-benzoquinone
-
A practical route is described for the flexible preparation of a wide variety of inositol stereoisomers and their polyphosphates. The potential of this approach is demonstrated by the synthesis of myo-, L-chiro-, D-chiro-, epi-, scyllo-, allo-, and neo-inositol systems. Optically pure compounds in either enantiomeric form can be prepared from p-benzoquinone via enzymatic resolution of a derived conduritol B key intermediate. High-performance anion-exchange chromatography with pulsed amperometric detection permits inositol stereoisomers to be resolved and detected with high sensitivity. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Podeschwa, Michael,Plettenburg, Oliver,Vom Brocke, Jochen,Block, Oliver,Adelt, Stephan,Altenbach, Hans-Josef
-
p. 1958 - 1972
(2007/10/03)
-
- Synthesis of haloconduritols from an endo-cycloadduct of furan and vinylene carbonate
-
A method for preparing haloconduritols having a conduritol-A construction is described. A mixture of endo- and exo-cycloadduct derivatives prepared from the Diels-Alder reaction of furan and vinylene carbonate was converted into diacetate derivatives by hydrolysis (K2CO3/MeOH) followed by acetylation (Ac2O/pyridine). Boron trihalide (BBr3 or BCl3)-assisted ring-opening of the endo-diacetate in CH2Cl2 at -78°C gave (1α,2α,3β,6β)-6-halogeno-4-cyclohexene-1,2,3-triol 1,2-diacetate from which the corresponding triacetate was prepared by acetylation (AcCl). trans-Esterification of the triacetate (MeOH/HCl) afforded (1α,2α,3β,6β)-6-halogeno-4-cyclohexene-1,2,3-triol (X=Br or Cl). BF3-Assisted ring-opening of the endo-diacetate in CH2Cl2 gave (1α,2α,3β,6β)-6-chloro-4-cyclohexene-1,2,3-triol 1,2-diacetate by means of halogen exchange.
- Baran, Arif,Kazaz, Cavit,Se?en, Hasan,Sütbeyaz, Ya?ar
-
p. 3643 - 3648
(2007/10/03)
-
- Asymmetric induction of conduritols via AAA reactions: Synthesis of the aminocyclohexitol of hygromycin A
-
Two synthetic routes towards the construction of the aminocyclohexitol moiety of hygromycin A have been developed based on palladium-catalyzed asymmetric alkylation of conduritol derivatives. A protocol has been established whereby this biologically relev
- Trost, Barry M.
-
p. 1619 - 1629
(2007/10/03)
-
- From cycloolefins to chiral, polyfunctionalized linear C6/C12 building blocks - Biocatalysis, (-)-conduramine E
-
1,4-Cyclohexadiene is the starting material for the expeditious synthesis of the 1S2S3S4R- and 1R2R3R4S-epoxy-cyclohexene-1,4-diol monoacetates through enzyme-catalyzed hydrolysis and transesterification, respectively. The absolute configurations are established by correlation of (-)-10 and known (+)-conduramine E. Ozonation and functional group manipulation open access to fully protected, polyfunctionalized C6-aldehydes whose reductive coupling to C2-symmetrical C12 building blocks is being explored. (C) 2000 Elsevier Science Ltd.
- Spielvogel,Kammerer,Keller,Prinzbach
-
p. 7863 - 7867
(2007/10/03)
-
- An efficient enzymatic preparation of (+)- and (-)-conduritol E, a cyclitol with C2 symmetry
-
Lypozyme IM (immobilised lipase from Mucor miehei) catalyses the enantiomeric alcoholysis of tetraacetylconduritol E (±)-2 to give enantiopure (1R,2R,3R,4R)-tetrahydroxycyclohex-5-ene (-)-1, and the unreacted ester (1S,2S,3S,4S)-tetraacetyloxycyclohex-5-ene, (+)-2. The latter was transformed by basic hydrolysis into (+)-1 in high yield and 95% ee. Selective amination of partial ester (-)-3, obtained by short alcoholysis of (±)-2, furnished the previously unreported conduramine F-4, (-)-4.
- Sanfilippo, Claudia,Patti, Angela,Piattelli, Mario,Nicolosi, Giovanni
-
p. 1569 - 1573
(2007/10/03)
-
- Stereochemical observations on the bromate induced monobromopentahydroxylation of benzene by catalytic photoinduced charge transfer osmylation. A concise synthesis of (±)-pinitol
-
The use of lower temperatures in the title reaction favours the formation of the neo diastereoisomer of the deoxybromoinositol whose diisopropylidene derivative can be converted in three steps to (±)-pinitol.
- Jung, Pierre M. J.,Motherwell, William B.,Williams, Alvin S.
-
p. 1283 - 1284
(2007/10/03)
-
- Improved preparation of (±)-(1,3/2,4)-5-cyclohexene-1,2,3,4-tetrol [(±)-conduritol-B] and its reaction with hydrobromic and hydrochloric acid; synthesis and characterisation of some (±)-1-deoxy-1-halo- and (±)-1,4-dideoxy-1,4-dihalo-conduritols
-
An active-site directed, covalent inhibitor of α-glucosidases is the mixture of (±)-1-bromo (1,3/2,4)-5-cyclohexene-2,3,4-triol [(±)-1-bromo-1-deoxyconduritol F] (2), formed on treatment of (±)-conduritol-B (3) with hydrogen bromide and termed 'bromo cond
- Guo,Haines,Pyke,Pyke,Taylor
-
p. 147 - 153
(2007/10/02)
-
- A novel synthesis of Conduritol-C and Conduritol-E via p-benzoquinone
-
A new and sterospecific synthesis for Conduritol-C 8 and Conduritol-E 13a has been developed starting from p-benzoquinone 1. 1,4-oxygen functionalities were introduced in both synthesis by the reduction of dibromo p-benzoquinone 2 with NaBH4. 2
- Secen,Maras,Sutbeyaz,Balci
-
p. 2613 - 2619
(2007/10/02)
-
- Catalytic One-Pot Osmylation of Cyclohexadienes: Stereochemical and Conformational Studies of the Resulting Polyols
-
Catalytic double osmylation is described for a series of cyclohexadienes in acetone/H2O in the presence of the co-oxidant N-methylmorpholine N-oxide (NMO).The formation of polyols occurred stereospecifically with cyclohexadienes 3, 7, and 11a, leading thereby to tetrols 5a, and 9a and to allo-inositol (14a), respectively.To the contrary, trans-cyclohexadiene-diol 15a gave a mixture of the stereoisomeric inositols 18a (epi), 19a (neo), and 20a (chiro).High-field NMR let to clearcut conformational analyses of the polyhydroxylated derivatives.
- Tschamber, Theophile,Backenstrass, Frederique,Fritz, Hans,Streith, Jacques
-
p. 1052 - 1060
(2007/10/02)
-
- SYNTHESIS OF BRANCHED-CHAIN CYCLITOLS USING A PALLADIUM(0)-CATALYZED ALLYLIC COUPLING REACTION
-
A carbanion derived from Meldrum's acid was used in a palladium(0)-catalysed allylic substitution reaction to prepare stereospecifically branched-chain cyclitols from the symmetrical 1,2,3,4-tetraacetoxycyclohex-5-ene (4).
- Barton, Derek H. R.,Dalko, Peter,Gero, Stephan D.
-
p. 2471 - 2474
(2007/10/02)
-
- A New and Stereospecific Synthesis of Conduritol-F and Conduritol-B
-
A new and stereospecific synthesis for conduritol-F has been developed starting from trans-benzenediacetate 5 and oxepine-benzeneoxide 8 where the oxygen functionalities were introduced in both cases by photooxygenation; suitable ring opening reactions gave the desired conduritol-F.Acid-catalyzed ring opening reaction of 11 in acetic anhydride gave conduritol-F and conduritol-B in a ratio of 2:1.
- Secen, Hasan,Suetbeyaz, Yasar,Balci, Metin
-
p. 1323 - 1326
(2007/10/02)
-