Bicyclo -2,2 -diol

Derivatives of CPD have also been incorporated into these resins. CPD and 2-butene-l,4-diol have been condensed in ethanol and catalyticaHy hydrogenated in situ to give 2,3-bis(hydroxymethyl)bicyclo[2.2.1]heptane (51). This latter compound is used as a chain extender in polyesters for engineering plastics (52). 

Cyclohex-2-enone- bicyclo [3.1.0] hexan-2-one rearrangement, 318 3a,5o -Cyclo-6/3,19-oxidocholestane, 268 18,20-Cyclo-5a-pregnane-3, 20-diol 3-acetate, 264... 

In a recent total synthesis of the novel neurotrophic agent merrilactone A (22, Scheme 4) by Inoue and Hirama [24], key intermediate 21 with the cis-bicyclo[3.3.0] octane framework embedded within the caged pentacycle 22 was elaborated from cyclobutane 18 by a sequence of RCM and immediate cleavage of the resulting bicyclic vicinal diol 19 to raeso-diketone 20. Cyclooctenedione 20 then underwent regioselective transannular aldol reaction at low temperature (LHMDS, THF, -100 °C) to produce a 3 1 mixture of isomers in 85% combined yield. The major isomer 21 with the required stereochemistry was then converted into the racemic natural compound ( )-22 in 19 steps. 

The reaction mixture is then extracted continuously with ether for 3 days. After extraction the ether is removed by rotary evaporation. The crude viscous liquid which results after evaporation (Note 7) is distilled (Note 8) under reduced pressure 106-111°C/0.06 mm) (11t. bp 90-96°C at 0.3 mm) to yield 14.5-16.2 g (83-93%) of 3, pure bicyclo[3.3.0]octane-2,6-diol, as a yellow viscous liquid (Note 9). 

Bicyclo-[2,2,l]-heptandiols-(2,3) neben 15% cis-Diol isoliert werden, das durch in diesem Fall reversible Dehydrierung iiber das Ketol entstanden sein muB (siehe Formelschema). 

Bicyclo-[l, 2, 2]-heptane-2,3-diol Cyclopentane-1,3-dicarboxylic acid B [33]... 

The system RuCl3/aq. Na(IO )/CeCl3.7H3O/EtOAc-CH3CN/0°C was used to cw-dihydroxylate 3-benzyloxy-2,2-difluoro-cyclo-oct-4Z-en-l-one to 3R -benzyloxy-2,2-difluoro-9-oxa-15, 5R -bicyclo[3.3.1]nona-15, 45 -diol and the... 

Disilyl ethers of bicyclo[2.2.0]hexane-l,4-diols were transformed to cyclohexane-1,4-diones by oxidation after hydrolysis in methanol to the diols, which can be isolated.100 Sodium periodate101-103 and molecular oxygen100,101,104 were used as oxidants. 

Bicyclo[3.2.0]heptane-l,5-diols are oxidized by Jead(IV) acetate35,36 or sodium periodate35 to give cycloheptane-1,4-diones. With lead(IV) acetate in acetic acid at 100 C substrates with a hydroxy group in -position to one of the newly formed carbonyl groups eliminate water to afford a,/ -unsaturated cycloheptanediones,36 and / ,y-double bonds migrate to the apposition.35... 

The central bond of bicyclo[4.2.0]octane-l,6-diol was cleaved by potassium periodate in water at room temperature to yield cyclooctane-1,4-dione.156... 

Similarly, androstane-5a,6a,17/ -triol 6-tosylate 17-benzoate (115b) is converted to 17/ -hydroxy-6/ -methyl-10(5 6jSH)afceo-androstan-5-one benzoate (116b) on treatment with calcium carbonate in dimethylformamide. Similar treatment of 10-methyldecalin-l,9-diol 1-tosylate (121) gives 10-methyl bicyclo [5.3.0]decan-1 -one (122). 

Decarbonylation is observed, however, in substituted 9,10-epoxycholestan-6-ones,104 and Norrish Type II photocyclization, leading to the formation of cyclobutanols, is preferred in other y-epoxy ketones.105 A photoreaction of a different type has been observed in the bicyclo[3.3.1]nonane (126) and affords the diol (127).106... 

Some ester- or aldehyde-substituted bicyclo[2.2.2]oct-2-ene and bicyclo[2.2.1]hept-2-ene systems (25) have been shown to undergo nitrosation adjacent to the carbonyl group followed by [3,3]-sigmatropic rearrangement to give oxazine products (26).23 Stereodeflned monoprotected allylic 1,2-diol (27) and its diastereomer have been ( ) converted into stereodeflned propenylimidazolidinone (30) and its diastereomer by... 

Photochemically induced transannular ring closure of bicyclo[3-3.1 -nonane-3,7-dione to 3,7-noradamantane diol is illustrated in Eq. (38)12S). 

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