Cis-l,2-Cyclohexanediol

STEREOSELECTIVE HYDROXYLATION WITH THALLIUM(I) ACETATE AND IODINE trans- AND cis-l,2-CYCLOHEXANEDIOLS... 

Osmium tetroxide is also a catalyst in the oxidation of the double bond by chlorates. Cis addition of hydroxyl groups takes place as is shown by the preparation of cis-l,2-cyclohexanediol from cyclohexene and the formation of the proper diastereoisomeric dihydroxy derivatives of maleic, fumaric, and 4-halocrotonic acids. Silver chlorate is preferred to potassium chlorate in the hydroxylation of crotonic acid. ... 

The stereochemistry of the diols often affects the yields of carbonyl compounds. Thus, the oxidation of cis-l,2-cyclohexanediol with sodium bismuthate in aqueous phosphoric acid and ether at 30 C gives only 23% of adipic aldehyde, whereas the trans isomer gives a 49% yield [483] (equation 303). 

Under a nitrogen atmosphere, 20 g (0.17 mol) of cis-l,2-cyclohexanediol is dissolved in 200 mL of dry benzene. Anhydrous potassium carbonate (50 g) is added, and the mixture is stirred vigorously while 76 g (0.17 mol) of lead tetraacetate is added in 5-g portions over a period of 1 h. After an additional hour of stirring, the mixture is filtered with suction, and the salts are extracted with benzene. The combined benzene solutions are dried over anhydrous sodium sulfate and evaporated in vacuo. The residue is distilled under a nitrogen atmosphere to give 13.4 g (68%) of colorless adipic aldehyde, bp 68-70 C at 3 mm of Hg. 

B. cis-l,2-Cyclohexanediol. A 500-ml., round-bottomed flask equipped with a reflux condenser and a magnetic stirring bar is charged with 17.56 g. (0.0667 mole) of thallium(I) acetate (Note 1), 160 ml. of glacial acetic acid, 3.0 g. (3.7 ml., 0.0365 mole) of cyclohexene (Note 3), and 8.46 g. (0.0333 mole) of iodine (Note 4) in the order given. The suspension is stirred and warmed in a heating bath at 80° for 30 minutes. An 80-ml. portion of water is added, stirring is continued, and the mixture is heated at reflux for... 

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-l,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 chloral and subsequent reduction. ... 

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... 

In several of the reactions in previous sections, one heteroatom (halogen, oxygen) was added to one side of a 7i-bond and a hydrogen or another heteroatom to the other side. There is another type of reaction in which heteroatoms are incorporated on both carbons of a 71-bond. A specific example incorporates two hydroxyl (OH) units. In one experiment, cyclohexene is treated with OSO4 (osmium tetroxide) in anhydrous er -butyl alcohol (2-methyl-2-propa-nol) at 0°C. After standing overnight, a 45% yield of cis-l,2-cyclohexanediol (124) was obtained.Analysis of this reaction shows that two OH units added and that both oxygen atoms were derived from osmium tetroxide. This reaction is termed a dihydroxylation. Furthermore, the two OH units have a cis relationship. 

While alcohols are converted to alkyl sulfates in the presence of sulfuric acid or a derivative, diols such as cis-l,2-cyclohexanediol form a dialkyl sulfate with a different structure. Speculate on the structure of the dialkyl sulfate derived from this diol. 

In Section 7.1, it was stated that interconversion of configurational isomers requires the cleavage and reformation of a chemical bond. Indicate any such bonds in cis-l,2-cyclohexanediol (6) that upon being broken and then reformed would afford the enantiomers 7 and 8. Be sure to describe what must occur stereochemically during the process of cleavage and remaking of a bond to effect the interconversion of 6 to the other two diastereomers. 

Scheme 6.9. A cartoon depiction of a possible path by which permanganate anion (Mn04") inbasicaqneonsmedinm yields (Z)-orcw-l,2-dihydroxycyclohexane(cis-l,2-cyclohexanediol). Note that the oxidation at carbon is accompanied by a redaction at manganese.

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