Polyhydroxylated cyclohexane derivatives

J. Marco-Contelles, C. Pozuelo, M. L. Jimeno, L. Martinez, and A. M. Grau, 6-exo Free radical cyclization of acyclic carbohydrate intermediates A new synthetic route to enantiomerically pure polyhydroxylated cyclohexane derivatives, J. Org. Chem. 57 2625 (1992). 

Marco-Contelles, J. et al. (5-Exo Free Radical Cyclizalion of Acyclic Carbohydrate Intermediates A New Synthetic Route to Enantiomerically Pure Polyhydroxylated Cyclohexane Derivatives. 3.1 1992 [144]... 

Microbial oxidation of benzene derivatives producing benzene cu-diols have been utilized in the preparation of 6-p-hydroxyshikimic acid, polyhydroxylated cyclohexane derivatives related to cyclophellitol and carba-a-L-fucose. It is worth noting here that the meso-6 o produced by oxidation of benzene itself has been resolved with a lipase giving (li , 2S)-l-acetoxy-2-hydroxycyclohexane-3,5-diene in >95% e.e. ... 

Intramolecular nitroaldol reactions are a useful choice for the conversion of sugars into polyhydroxylated nitro cyclopentanes, nitro cyclohexanes and their derivatives.46 Baer et al. in the course of their studies on the cyclization of 6-deoxy-6-nitrohexoses under kinetic and thermodynamic control,47 established the reaction pathway involved in the formation of nitroinositols mediated by intramolecular Henry reactions. Firstly, a nitronate is formed and then, under thermodynamic control conditions, an epimerization occurs before cyclization. But, under kinetic controlled conditions, the cyclization occurs first.48... 

Twenty-five ecdysteroids, derived irom 20-hydroxyecdysone, were studied in both normal-phase (silica column) and reversed-phase (Cig column) modes. IPA/dichloromethane/water (30/125/2), IPA/cyclohexane/water (40/400/3), or IPA/iso-octane/water (30/100/2) was selected as NP mobile phase. Here is an instance where the water concentration in a immiscible matrix (e.g., iso-octane) is increased due to the presence of a mutually miscible solvent, IPA. Methanol/water (50/50), ethanol/water (30/70), or IPA/water (18/72), all containing 0.1% TEA, were studied as reversed-phase mobile phases [423]. Methanol proved particularly effective in the RP separation of analytes that varied by the degree of unsaturation (i.e., number of double bonds). IPA, as a RP solvent, was superior in resolving 5a-5jS pairs. IPA was extremely effective in the separation of 20-hydroxyecdysone and polypodine B mixtures. These results are not surprising since ecdysones are polyhydroxylated. 

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