Trans-7,2-Cyclohexanediol, preparation

The preparation of Pans-1,2-cyclohexanediol by oxidation of cyclohexene with peroxyformic acid and subsequent hydrolysis of the diol monoformate has been described, and other methods for the preparation of both cis- and trans-l,2-cyclohexanediols were cited. Subsequently the trans diol has been prepared by oxidation of cyclohexene with various peroxy acids, with hydrogen peroxide and selenium dioxide, and with iodine and silver acetate by the Prevost reaction. Alternative methods for preparing the trans isomer are hydroboration of various enol derivatives of cyclohexanone and reduction of Pans-2-cyclohexen-l-ol epoxide with lithium aluminum hydride. cis-1,2-Cyclohexanediol has been prepared by cis hydroxylation of cyclohexene with various reagents or catalysts derived from osmium tetroxide, by solvolysis of Pans-2-halocyclohexanol esters in a manner similar to the Woodward-Prevost reaction, by reduction of cis-2-cyclohexen-l-ol epoxide with lithium aluminum hydride, and by oxymercuration of 2-cyclohexen-l-ol with mercury(II) trifluoro-acetate in the presence of ehloral and subsequent reduction. ... 

High levels of asymmetric induction can be achieved intramolecularly if the substrate functionality and the heteroatom ligand are contained in the same molecule. Chiral amido(a]kyl)cuprates derived from allylic carbamates [(RCH= CHCH20C(0)NR )CuR undergo intramolecular allylic rearrangements with excellent enantioselectivities (R = Me, n-Bu, Ph 82-95% ee) [216]. Similarly, chiral alkoxy(alkyl)cuprates (R OCuRLi) derived from enoates prepared from the unsaturated acids and trans-l,2-cyclohexanediol undergo intramolecular conjugate additions with excellent diasteroselectivities (90% ds) [217]. 

There have been a few reports on the controlled catalytic alcoholysis of dialkylsilanes to produce the mono-hydrido silyl ether. 9a,c,15 16 One such report is by Corriu and Moreau who have illustrated the use of either (PPh3)3RJiCl, (PPh3)3RuCl or Raney Ni to execute the controlled alcoholysis of diphenylsilane to give the mono-functional alkoxysilane as the only product.93 Doyle attempted to use the Rh2(pfb)4 catalyst with diphenylsilane and trans- 1,2-cyclohexanediol to prepare the cyclic silyl ketal,16 but this was not successful, perhaps because the trans-fused... 

The method described is essentially that of Swem, Billen, Findley, and Scanlan. /mM5-l,2-Cyclohexanediol also has been prepared by hydrolysis of cyclohexene oxide. j-l,2-Cydo-hexanediol has been prepared by the reaction of cyclohexene with hydrogen peroxide in tertiary butyl alcohol with osmium tetroxide as a catalyst. Hydrogenation of catechol over Raney nickel catalyst at 150° gives a mixture (m.p. 73-77°) of cis- and trans-1,2-cyclohexanediols. ... 

ROM—>RBr. In the cyclohexane series reaction of diols with PBr is attended with rearrangements. Thus treatment of the 1,3- and 1,4-cyclohexanediols with PBrj affords mixtures of cis- and trans-1,3- and l,4-dibromides. Eliel and Haber found that cu-d-i-butylcyclohexanol reacts with PBr to give trani-4-/-butylcyclo-hexyl bromide, together with a small amount of olefin and a mixture of dibromides. Thus PBr, is evidently superior to PBr, for conversion of secondary alcohols into bromides. However, the Hunsdiecker reaction seems to be the method of choice for preparation of cyclohexyl bromides. ... 

---