Diols from dialdehydes

Cyclic 2>nitro l,3>diols from dialdehydes Aliphatic nitro compounds from aci-nitro compounds by dry acidification... 

Cyclic ethers can also be formed in a fashion similar to that of the reactions described previously (Eq. 186),306,342 and also result from the reductive etherification of bis(trimethylsilylated) diols and dialdehydes (Eq. 187).343... 

Iodine triacetate, IfOCOCHsIj, which is prepared from iodine trichloride and silver acetate in acetic acid at room temperature, cleaves vicinal diols to dialdehydes [779]. 

Cyclopentene-l-carboxaldehydes are obtained from cyclohexene precursors by the sequence cyclohexene - cyclohexane-1,2-diol -> open-chain dialdehyde - cyclopentane aldol. The main advantage of this ring contraction procedure is, that the regio-and stereoselectivity of the Diels-Alder synthesis of cyclohexene derivatives can be transferred to cyclopentane synthesis (G. Stork, 1953 G. BUchi, 1968). 

Much of the chemistry of diols—compounds that bear two hydroxyl groups—is analo gous to that of alcohols Diols may be prepared for example from compounds that con tain two carbonyl groups using the same reducing agents employed m the preparation of alcohols The following example shows the conversion of a dialdehyde to a diol by... 

Labelled mevalonic acid dibenzylethylenediamine (DBED) salt (14 pCi) was injected into the digestive glands of D. limbata [90]. After 24 h, the animals were sacrificed and labelled polygodial (30) was recovered from the skin of the mollusc. After two subsequent chromatographic purifications, the dialdehyde was reduced to the corresponding diol (35) which was significantly labelled. The ability of D. limbata to synthesize de novo its own defensive allomone raised a series of questions linked to... 

Fig. 10.30. Structure of aflatoxin B1 exo-8,9-epoxide (10.132), the dihydrodiol resulting from hydrolysis (10.133), and the reactive a-hydroxy dialdehyde (10.134) that exists in equilibrium with the diol under alkaline conditions [204]...

The configuration of the products was established by periodate oxidation of the D compound, and reduction of the resulting dialdehyde to an optically active diol whose sign and magnitude of optical rotation ([a] ° +2.5° in water) correspond to that of the diol ([a]n° 46.8° in water) obtained by similar treatment of methyl a-L-arabinopyrano-side. The bis(p-nitrobenzoates) of the two diols exhibited similar relationships. Hence, it appears likely that the configuration at C-2 of the anhydride is the same as that at C-l of the L-arabinoside. The cis relationship of the hydroxyl groups was retained from the arabinal started with. 

Furans have been prepared from 1,4-dialdehydes, usually in the more accessible acetal form by acid catalyzed ring closure. Using this approach, furan-3,4-dicarboxyIic acid has been obtained in 70% yield as the ester from 2-(dialkoxymethyl)-l-formyl succinic ester (54JOC1671). c/s-2-Butene-l,4-diol on oxidation to the monoaldehyde is cyclized to furan (61 ACSll77). The acetals (83) and (84) have been converted to the corresponding furan... 

Perhydro-diazocines 28, for the preparation of l,4-diamino-2,3-diol units that are the central structural elements in numerous biomaterials, were obtained from 1,3-cyclooctadiene, by reaction with diethyl azodicarboxylate (DEAD) to give the bridged 1,2-diazocine 103, which by ozonolysis gave the dialdehyde 104 that underwent... 

The scope of the 2-azadiene intramolecular Diels-Alder cyclization, employed for the synthesis of the daphniphyllum alkaloids, has been further investigated by Heathcock et al.[76j. The protocol involves Moffatt-Swem oxidation of the 1,5-diol to the dialdehyde, and treatment of the crude methylene chloride solution with ammonia followed by solvent exchange from methylene chloride to a buffered acetic add solution. The cydopentyl ring, quaternary carbon and tertiary carbon centers in... 

The first total synthesis of ( )-sarcophytol B (5) from S./i-famesal (92), which was reported by McMurry et al. in 1989, used a low-temperature titanium-induced pinacol coupling reaction of 1,14-dialdehyde as the key step. They concluded that the natural sarcophytol B has the stereochemistry of a trans diol (Scheme 6-5). Li et al. reported on a concise total synthesis of ( )-sarcophytol B (5) from /i./i-famesol (91) by a low-valent titanium-mediated intramolecular McMurry... 

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