Diols with chromium trioxide

Cyclopentene-l,4-dione has been prepared by oxidation of 2-cyclopentene-l,4-diol with chromium trioxide in aqueous acetic acid or in aqueous acetone, and with silver chromate. The present method eliminates the tedious removal of large amounts of acetic acid and gives a higher yield. 

The mixture 258 was converted to the unstable benzenesulfonyl aziridine 259 by treatment with an excess of benzenesulfonyl azide in benzene. Ace-tolysis of 259 with acetic acid and sodium acetate at room temperature for several days afforded the crystalline mixture of diastereoisomers represented by the formula 260. The aziridine rearrangement was regiospecific and 260 was the only product detected during this rearrangement. Lithium aluminium hydride reduction of 260 followed by acetylation yielded the mixture 261 in 85% yield. Selective hydrolysis of 261 afforded 262 in quantitative yield. The diastereoisomeric mixture 262 was converted into the diols 263 by hydrogenolysis. The diol mixture was oxidized with chromium trioxide... 

A - -Steroid. Dauben and Fullerton chose the following route for conversion of A -androstenc-.3)S,17 -diol diacetate (1) into A - -androstadiene-3, 17 -diol diacetatc (4). The starting material was converted into the 7-ketonc (2) by oxidation with chromium trioxide-pyridine complex in methylene chloride (2, 74 75). The ketone OAc... 

A mixture of cis- and trart5-l,2-dimethylacenaphthene-l,2-diol dissolved in acetic acid is oxidized with chromium trioxide to 1,8-diacetyl-naphthalene in 89% yield [5SS]. The treatment of 17p,17ap-dimethyl-D-homoandrostane-33,17ct,17aa-triol 33-acetate with chromium trioxide or with sodium bismuthate yields 33-acetoxy-17,17a-dimethyl-17,17a-seco-homoandrostane-17,17a-dione (equation 305) [482. ... 

The diketone (3) Is a versatile intermediate for the preparation of 9-thiabicyclo[3.3.1]nonane derivatives and provides a simple synthetic entry to a number of other heterocycles such as the 2-thiaadamantane. 3 4 thiacyclohexane, thiacycloheptane, 2,6-dlthiaadamantane, 6 and 2-thiabrexane 7 ring systems. Only one previous procedure for Its preparation has been published. This method involves the oxidation of diol (2) with chromium trioxide in pyridine and diohioromethane to yield 9-thiabicyclo[3.3.1]nonane-2,6-dione (3) in 65% yield. In practice this reaction Is difficult to carry out reproducibly because of precipitation of tarry chromium salts which make adequate stirring and extraction of the product very difficult. Consequently the dione (3) is often accompanied by partly oxidized material and/or material where the sulfur atom has been oxidized. The method reported here avoids these technical difficulties and affords a considerably Increased yield. 

In contrast to the usual reaction of aromatic aldehydes with cyclic ketones o-nitrobenzaldehyde condenses with 17-ketones to produce good yields of seco-acids, a reaction which has been applied to the preparation of 16-oxa-steroids. Thus, 3 -hydroxy-5a-androstan-17-one or its acetate affords the seco-steroid (153), which can be oxidised either as the free acid by ozone and alkaline hydrogen peroxide to the diacid (155) or, as its methyl ester (154), with chromium trioxide to the monomethyl ester (156). Diborane reduction of the diacid (155) or lithium aluminium hydride reduction of the dimethyl ester (157) gave the trans-diol (158), cyclised with toluene-p-sulphonic acid to 16-oxa-androstan-3)5-ol (159) or, by oxidation with Jones reagent to the lactone (152) (as 3-ketone) in quantitative yield. This lactone could also be obtained by lithium borohydride reduction of the monomethyl ester (156), whilst diborane reduction of (156) and cyclisation of the resulting (151) afforded the isomeric lactone (150). The diacid (155) reacted with acetic anhydride to afford exclusively the cis-anhydride (161) which was reduced directly with lithium aluminium hydride to the cis-lactone (160) or, as its derived dimethyl ester (162) to the cis-diol (163) which cyclised to 16-oxa-14)5-androstan-3) -ol (164). 

Oxidation of lappaconitine with chromium trioxide in acetone followed by basic hydrolysis afforded a lactam-cyclopentanone. The identical lactam was also obtained by the oxidation of lappaconine with chromium trioxide in acetone. Only a vicinal diol (C-8 and C-9) could give rise to such an oxidation product thus, Yunusov and his colleagues (109) assigned the N -acetylanthranilic ester moiety to the C-4 position in lappaconitine. Recently, we have confirmed (110) this assignment by 13CNMR analysis of lappaconitine (87) and lappaconine (86). 

Racemic trans-l,2-dihydro-l,2-dihydn>xyacronycine (158) was first obtained in very low yield by oxidation of acronydne (2) with chromium trioxide in acetic add followed by alkaline hydrolysis of the intomediate troru-diol monoacetate 274). A more convenient access was recently described 371), based on a previous shufy of the oxidation of acronydne by potassium permanganate 372). Thus, treatment of acronycine (2) with potassium permanganate in aqueous acetone gave l-oxo-2-hydroxy-l,2-dihydroacronydne (376) in 31% yield, accompanied by smaller amounts of c -l,2-dihydro-l,2-dihydroxyacronydne (157) and of the acetone adduct 377. Sodium borohydride reduction of l-oxo-2-hydroxy-... 

Addition of 4-pentenyllithium to the dione 65 gave the ds-diol 71 which was converted to the (Z)-l,2-disubstituted cyclododecene 72a. Hydroboration-oxidation and chromium trioxide oxidation provided the dialdehyde 72b whose McMurry ring closure, followed by partial catalytic hydrogenation gave the (Z)[10.10] precursor 73. Treatment of this (Z)-olefin 73 with HzS04-Ac0H in benzene was reported to effect conversion into [10.10]betweenanene (61b) of 95% purity and high yield. 

The oxidation of diols having alcoholic groups of the same nature, for example, both alcoholic groups are primary, secondary, allylic, or benzylic, is usually carried out at both groups to yield dialdehydes [832] or diketones [552], Such reactions are achieved by chromium trioxide [582], barium manganate [832], dimethyl sulfoxide activated with acetic anhydride [1013], and others (equations 284 and 285). 

Two oxidants essentially dominate these oxidations lead tetraacetate in organic solvents and periodic acid in aqueous media. On occasion, other oxidation reagents cause the cleavage of vicinal diols ceric ammonium nitrate [424], sodium bismuthate [482, 483], chromium trioxide [482, 555], potassium dichromate with perchloric acid [949], manganese dioxide [817], and trivalent [779, 789] or pentavalent [798] iodine compounds. 

The Diels-Alder reaction was utilized to construct bicyclo [2.2 1]heptane or bicyclo[2 2 l]heptene structures The reaction of isopropylidenecyclopentadiene with maleic anhydride produced the endo and exo configurational isomers of 8-isopropylidenebicyclo[2.2.1] hept-2-ene-5,6-dicarboxylic anhydride Similar reactions were applied to unsubstituted and l-(methoxycarbonyl)cyclopentadienes to give the corresponding anhydrides The anhydrides were reduced to alcohols, which were then allowed to react with thionyl chloride or tosyl chloride to give cyclic sulfites or tosylates Reaction of the tosylates with lithium chloride gave chlorinated compounds Hydration of the double bonds of the chlorinated compounds was accomplished by hydroboration-oxidation Diol 31 thus obtained was converted to 5,6-bis(chloromethyl)-7-isopropylidene-bicyclo[2 2 1] heptan-2-one [33] by chromium trioxide oxidation of the secondary hydroxyl group followed by dehydration at the C-7 substituent. 

The synthesis of verazine [(25S)-22,26-epiminocholesta-5,22(iV)-dien-3/3-ol)] (95) from tomatid-5-en-3/S-ol was described [64-66). Reduction of 86 with sodium borohydride in methanol afforded diol 87 which, when acetylated, furnished the iV,0,C>-fn-acetate (88). Alkaline hydrolysis of 88 yielded the diol 89. Through partial oxidation with one equivalent of chromium trioxide, the A-acetyldiol (89) gave the ketone 90. Treatment of this ketone with ethanedithiol—hydrochloric acid, followed by desulfurization of the resulting thioketal 91 with Raney nickel, yielded 92. 

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