- Stereoselective syntheses of racemic quercitols and bromoquercitols starting from cyclohexa-1,4-diene: Gala-, epi-, muco-, and neo-quercitol
-
The efficient synthesis of gala-, epi-, neo-, and muco-quercitols and some brominated quercitols starting from cyclohexa-1,4-diene is reported. Treatment of the dibromide, obtained by the addition of bromine to cyclohexa-1,4-diene, with m-chloroperbenzoic
- Aydin, G?kay,Savran, Tahir,Akta?, Fatih,Baran, Arif,Balci, Metin
-
p. 1511 - 1524
(2013/05/21)
-
- Stereoselective syntheses of (+)-proto, (-)-gala quercitols and carba-l-rhamnose from d-(-)-quinic acid
-
Efficient syntheses of (+)-proto, (-)-gala quercitols and carba-l-rhamnose from d-(-)-quinic acid are described.
- Murugan, Andiappan,Yadav, Anuj K.,Gurjar, Mukund K.
-
p. 6235 - 6238
(2007/10/03)
-
- Resolution of (±)-anti-2,3-dioxabicyclo[2.2.2]oct-7-en-5-ol via Candida cylindracea lipase: Synthesis of (-)- and (+)-proto-quercitol
-
Photooxygenation of cyclohexa-1,4-diene afforded anti-2,3-dioxabicyclo[2.2. 2]oct-7-en-5-yl hydroperoxide. The hydroperoxy endoperoxide was reduced with dimethylsulfide-titanium tetraisopropoxide to produce (±)-anti-2,3- dioxabicyclo[2.2.2]oct-7-en-5-ol. The highly efficient enantioselective resolution of the racemic (±)-anti-2,3-dioxabicyclo[2.2.2]oct-7-en-5-ol was accomplished with Candida cylindracea lipase (CCL) to produce the enantiomerically enriched alcohol and the corresponding acetate: The cleavage of the peroxide linkage by thiourea followed by the oxidation of the double bond with OsO4 resulted in the formation of (-)-proto-quercitol and (+)-proto-quercitol, respectively.
- Gueltekin, M. Serdar,Celik, Murat,Turkut, Engin,Tanyeli, Cihangir,Balci, Metin
-
p. 453 - 456
(2007/10/03)
-
- A facile synthesis of a new trihydroxy piperidine derivative and (+)-proto-quercitol from D-(-)-quinic acid
-
We described herein the new synthesis of a trihydroxy piperidine derivative (1,4,5-trideoxy-1,5-imino-D-ribo-hexitol) and (+)-proto-quercitol from D-(-)-quinic acid, both are considered as inhibitors for glycosidases.
- Shih, Tzenge-Lien,Kuo, Wei-Shen,Lin, Ya-Ling
-
p. 5751 - 5754
(2007/10/03)
-
- An efficient and highly stereoselective synthesis of gala-Quercitol from 1,4-cyclohexadiene
-
gala-Quercitol was synthesized from 1,4-cyclohexadiene in seven steps and overall yield of 68%. Reaction of 5,6-dibromo-2,2-dimethylhexahydro-1,3-benzodioxole, synthesized from 1,4-cyclohexadiene in three steps, with excess NaOMe gave (3aα,5α,7aα)-5-metho
- Baran, Arif,Secen, Hasan,Balci, Metin
-
p. 1500 - 1502
(2007/10/03)
-
- An Advantageous Synthesis of 1D- and 1L-1,2,3,5/4-Cyclohexanepentol
-
The title compounds D-10 and L-10 were prepared from 1 in eight steps and in a combined overall yield of 41-49%.
- Biamonte, Marco A.,Vasella, Andrea
-
p. 688 - 694
(2007/10/03)
-
- A novel synthesis of DL-proto-, and DL-vibo- quercitol via 1,4- cyclohexadiene
-
Photooxygenation of 1,4-cyclohexadiene 3 followed by reduction with LiAIH4 or thiourea gave (25/1)-cyclohex-3-ene-triol 7a. trans-Hydroxylation of triol 7a with three different methods afforded both of proto-quercitol 1a and vibo-quercitol 2a.
- Salamci, Emine,Secen, Hasan,Suetbeyaz, Yasar,Balci, Metin
-
p. 2223 - 2234
(2007/10/03)
-
- A concise and convenient synthesis of DL-proto-quercitol and DL-gala-quercitol via ene reaction of singlet oxygen combined with [2 + 4] cycloaddition to cyclohexadiene
-
Photooxygenation of 1,4-cyclohexadiene afforded hydroperoxy endoperoxides 3 and 4 in a ratio of 88:12. Reduction of 3 with LiAlH4 or thiourea followed by acetylation of the hydroxyl group and KMnO4 oxidation of the double bond gave proto-quercitol 10b. Application of the same reaction sequences to 4 resulted in the formation of gala-quercitol 14. Quercitols were easily obtained by ammonolysis of acetate derivatives in MeOH. The outcome of dihydroxylation reactions were supported by conformational analysis.
- Salamci,Secen,Sutbeyaz,Balci
-
p. 2453 - 2457
(2007/10/03)
-
- A Stereocontrolled Synthesis of proto-Quercitol
-
Conduritol A tetramethyl ether (2) has been converted by hydroboration-oxidation into proto-quercitol tetramethyl ether (5) which on demethylation afforded a mixture (2:1) of proto-quercitol (4) and vibo-quercitol (11). proto-Quecitol was also obtained (15percent) from conduritol A tetrabenzoate (3) by a similar sequence.
- Cambie, Richard C.,Renner, Noel D.,Rutledge, Peter S.,Woodgate, Paul D.
-
p. 1597 - 1602
(2007/10/02)
-
- MICROBIAL OXIDATION IN SYNTHESIS: PREPARATION OF MYO-INOSITOL PHOSPHATES AND RELATED CYCLITOL DERIVATIVES FROM BENZENE.
-
Pseudomonas putida oxidation of benzene affords cis-3,5-cyclohexadiene-1,2-diol (2) which is used as a novel precursor for the synthesis of D- and L-myo-inositol 1,4,5-triphosphates, (-)-(1) and (+)-(1).The versatility of this approach to functionalised cyclitols is illustrated in the synthesis of myo-inositol 1-phosphate (19), 6-deoxy, 6-deoxy-6-fluoro, and 6-deoxy-6-methyl myo-inositols (31), (37) and (43), and their 1,4,5-trisphosphate derivatives (33), (39) and (45).
- Ley, Steven V.,Parra, Margarita,Redgrave, Alison J.,Sternfeld, Francine
-
p. 4994 - 5026
(2007/10/02)
-
- Tannins and Related Compounds. XX. Two New Ellagitannins Containing a Proto-quercitol Core from Quercus stenophylla Makino. (4)
-
A new class of ellagitannins (1 and 2) possessing a proto-quercitol moiety has been isolated from the bark of Quercus stenophylla Makino (Fagaceae), and their structures have been characterized from the chemical and spectroscopic evidence as 1,5-di-O-galloyl-3,4-(S)-hexahydroxydiphenoyl proto-quercitol (1) and 5-O-galloyl-3,4-(S)-hexahydroxydiphenoyl proto-quercitol (2).Keywords - Quercus stenophylla; Fagaceae; ellagitannin; proto-quercitol; tannase; 1H-NMR; spin-decoupling
- Nishimura, Hiroaki,Nonaka, Gen-ichiro,Nishioka, Itsuo
-
p. 1750 - 1753
(2007/10/02)
-
- Polyfunctionalised Cyclohexanes from Dianhydrodeoxyinositols. cis-Deoxy-1,3(1,4)-inosadiamines from Benzene
-
A ca. 9 : 1 mixture (yield 87 - 90percent) of the stereoisomeric (1α,2α,6α)-/(1α,2β,6α)-2-bromo-7-oxa-bicyclohept-3-enes (7a/8a) is obtained via controlled NBS bromination of 4,5-epoxycyclohexene (5). 7a/8a are quantitatively equilibrated in the presence of tetraalkylammonium bromides (the equilibrium being controlled by the polarity of the solvent (3 : 7 in acetonitrile) and are isolated pure by chromatography.Through selective halogen substitution (7b/8b, 9b - d/10b - d) and ammonolysis the allylic epoxy alcohols 9a/10a are obtained in high yields.Stereospecific epoxidation of 7a/8a yields the (1α,2α,3α,5α,7α)-/(1α,2β,3α,5α,7α)-diepoxy bromides 12a/14a.The latter are equilibrated quantitatively to mixtures favoring either one in the ratio of ca. 9 : 1 (CCl4) and 1 : 9 (CH3CN), respectively.Upon SN2 substitution with ammonium acylates (-> 13b, c/15b, c) and ammonolysis the naturally not occurring dianhydrodeoxyinositols 13a/15a are isolated in practically quantitative yields.The usefulness of 13a/15a and of various derivatives for the stereoselective synthesis of cis-1,4- and cis-1,3-disubstituted cyclohexanetriols is exemplified by reactions with monovalent (H2O, HI, NaN3) and divalent nucleophiles (NH2NH2, CH3NHNH2).I.a. the cis-deoxy-1,3-inosadiamines 1 (2-deoxystreptamine)/2 and the cis-deoxy-1,4-inosadiamines 3/4 become available in high yields.
- Kuehlmeyer, Rainer,Keller, Reinhold,Schwesinger, Reinhard,Netscher, Thomas,Fritz, Hans,Prinzbach, Horst
-
p. 1765 - 1800
(2007/10/02)
-
- THE PREPARATION OF CYCLOHEXANEPENTOLS FROM INOSITOLS BY DEOXYGENATION
-
Several cyclohexapenetols heva been synthesized from inositols by blocking all but one hydroxyl group, converting the free hydroxyl group into its S-methyl dithiocarbonate, and treating it with tributylstannane.Suitable blocking-groups are methyl, benzyl, and methylthiomethyl ethers, and acetals.One cyclohexanepentol was prepared by the reductive deamination of an aminodeoxyinositol.
- Angyal, Stephen J.,Odier, Leon
-
p. 209 - 220
(2007/10/02)
-
