title: Concentrated hydriodic acid in simultaneous deprotections of multifunctional inositols.
abstract: 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.
authors.affiliation: Institut für Chemie, Universität Rostock, Albert-Einstein-Strasse 3a, D-18059 Rostock, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Miethchen
authors.forename: Andreas
authors.initials: A
authors.lastname: Schmidt
authors.forename: Katharina
authors.initials: K
authors.lastname: Neitzel
authors.forename: Manfred
authors.initials: M
authors.lastname: Michalik
authors.forename: Thomas
authors.initials: T
authors.lastname: Pundt
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Ruth
mesh_terms: D000143:Acids / Q000737:chemistry*; D002855:Chromatography, Thin Layer; D007294:Inositol / Q000737:chemistry*; D017613:Iodine Compounds / Q000737:chemistry*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009904:Optical Rotation; D013237:Stereoisomerism
chemical_list: D000143:Acids; D017613:Iodine Compounds; D007294:Inositol; C010466:hydroiodic acid