18779-57-2Relevant academic research and scientific papers
Site-selective benzoin-type cyclization of unsymmetrical dialdoses catalyzed by N-heterocyclic carbenes for divergent cyclitol synthesis
Kang, Bubwoong,Wang, Yinli,Kuwano, Satoru,Yamaoka, Yousuke,Takasu, Kiyosei,Yamada, Ken-Ichi
supporting information, p. 4469 - 4472 (2017/04/26)
A highly site-selective N-heterocyclic carbene (NHC)-catalyzed benzoin-type cyclization of unsymmetrical dialdoses is developed to enable a divergent cyclitol synthesis. The choice of chiral NHCs and protecting groups affects the site-selectivity. The resulting inososes are converted into epi-, muco- and myo-inositols, and their chiral protected derivatives are formed in good yields.
Concentrated hydriodic acid in simultaneous deprotections of multifunctional inositols
Miethchen, Ralf,Schmidt, Andreas,Neitzel, Katharina,Michalik, Manfred,Pundt, Thomas,Ruth, Wolfgang
, p. 741 - 748 (2007/10/03)
L-1-Deoxy-1-fluoro-6-O-methyl-myo-inositol was epimerized by chloral/DCC in boiling 1,2-dichloroethane yielding d-1-O-cyclohexylcarbamoyl-2-deoxy-2-fluoro- 3-O-methyl-5,6-O-[(R/S)-2,2,2-trichloroethylidene]-chiro-inositol. The latter and l-4-O-benzyl-3-O-cyclohexylcarbamoyl-5-O-methyl-1,2-O-(2,2,2- trichloroethylidene)-muco-inositol, l-4-O-benzyl-3-O-cyclohexylcarbamoyl-1,2-O- ethylidene-5-O-methyl-muco-inositol, d-1-O-cyclohexylcarbamoyl-2-deoxy-5,6-O- ethylidene-2-fluoro-3-O-methyl-chiro-inositol, as well as d-5-O-benzyl-4-O- cyclohexylcarbamoyl-3-deoxy-3-(N,N′-dicyclohexylureido)-6-O-methyl-1, 2-O-(2,2,2-trichloroethylidene)-chiro-inositol were deprotected with boiling 57% aq hydrogen iodide. Ether, urethane and ethylidene acetal functions were simultaneously cleaved by the reagent, whereas the trichloroethylidene groups were still intact or were only removed in small quantities. Especially, the urea function of d-5-O-benzyl-4-O-cyclohexylcarbamoyl-3-deoxy-3-(N,N′- dicyclohexylureido)-6-O-methyl-1,2-O-(2,2,2-trichloroethylidene)-chiro-inositol was decomposed to a cyclohexylamino group. The hydrodechlorination of d-1-O-cyclohexylcarbamoyl-2-deoxy-2-fluoro-3-O-methyl-5,6-O-[(R/S)-2,2, 2-trichloroethylidene]-chiro-inositol using Raney-Nickel yielded a mixture of the corresponding 5,6-O-ethylidene- and 5,6-O-chloroethylidene derivatives. The three synthetic steps-hydrodehalogenation, HI-deprotection and peracylation- were combined without purification of the intermediates.
Catalytic One-Pot Osmylation of Cyclohexadienes: Stereochemical and Conformational Studies of the Resulting Polyols
Tschamber, Theophile,Backenstrass, Frederique,Fritz, Hans,Streith, Jacques
, p. 1052 - 1060 (2007/10/02)
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.
