C/s-l,2-Cyclohexanediol

Little related work on the technetium analog has been completed. Much of the synthetic work with high-valent Tc has centered on imido complexes,54 or on complexes for use in radiopharmaceuticals.55 Methyl technetium trioxide has been prepared.8 This species is thermodynamically a powerful enough oxidant to cycloadd to alkenes cyclohexene gave (after hydrolysis) c/s-l,2-cyclohexanediol. No chemistry with H202 has been reported it is expected to behave in a similar manner to MTO, unless the change in the metal-oxo bond strength perturbs the overall thermodynamics. 

Figure 3.22 Sensitivity of PABA to D-fructose ( ), D-glucose (O), ds-l,2-cyclo-pentanediol ( ), fra s-l,2-cyclopentanediol (A), c/s-l,2-cyclohexandiol ( ), and fra i-l,2-cyclohexanediol (A) and in PBS. (Reprinted with permission from Journal of the American Chemical Society, 124, 12486. Copyright (2002) American Chemical Society.)...

The reaction of cis-l,2-cyclohexanediol (16) with DTPP affords bicyclic 1,3,2X5-dioxaphospholane 11 which thermally decomposes to cyclohexanone (18) via a 1,2-hydride migration process (e.g., L in Scheme 6) (76). The reaction of dioxaphospholane 17 with LiBr in THF solvent is characterized by a pseudo-first order rate constant, kLiBr = 9.2 x 10 s at 52°C (29). Moreover, the reaction of... 

The most common stereoselective syntheses involve the formation and cleavage of cyclopentane and cyclohexane derivatives or their unsaturated analogues. The target molecule (a//-c/s)-2-methy 1-1,4-cyclohexanediol has all of its substituents on the same side of the ring. Such a compound can be obtained by catalytic hydrogenation of a planar cyclic precursor. Methyl-l,4-benzoquinone is an ideal choice (p-toluquinone M. Nakazaki, 1966). 

A mixture of tranj,tranj-2-nitro-l,3-cyclohexanediol diacetate in tetrahydrofuran and coned, aq. NHg vigorously stirred at 40° for 8 hrs., the resulting crude diamine dissolved in methanol, ice-cooled, treated with acetic anhydride, and allowed to stand at room temp, overnight -> tra/i5,trtm5-l,3-diacetamido-2-nitro-cyclohexane. Y 70.5%. H. H. Baer and M. C. T. Wang, Can. J. Chem. 46, 2793 (1968) also with benzylamine, preferential replacement, nucleosides, s. F. W. Lichtenthaler, G. Trummlitz, and H. Zinke, Tetrah. Let. 1969, 1213. 

The Abu-Omar group demonstrated that, in the absence of an added reductant, MeReO (MTO) catalyzes redox disproportionation of glycols. Glycerol was shown to serve as both substrate and reductant (165 C, 2 mol% MTO) in a reactive distillation process, producing moderate yields of volatile allyl alcohol, acrolein, and propanal (1.0 0.22 0.15), and non-volatile, reactive l,3-dihydroxyacet(Mie (Scheme 18). Redox disproportionation of c/s-cyclohexanediol catalyzed by MTO was also efficient producing cyclohexene and 1,2-cyclohexanedione [37]. The rate of the glycerol reaction was determined to be first-order in the diol and first-order in MTO and a kinetic isotope effect of 2.4 was measured for... 

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