Butane-1,2,4-triols

A cyclic carbonate was utilized as a protecting group for the cw-diol system in butane-1,2,4-triol ... 

Having established the origin of the rotamers Gl, G2 and G3, the splitting within each of these groups into further components due to the chiral centres in the amide side-chains was to be examined. These polyhydroxylated side-chains contain solely the threo (RS) form of 3-amino-butane-1,2,4-triol as a racemate (Fig. 19). Accordingly, from the possible 8 chiral centres only 4 have to be taken into consideration. These would lead - without considering other types of isomerism - to 16 isomers (8 pairs of isomers). Including (E)I(Z) isomerism, 48 isomers can be expected. 

Assuming that the synthesis, i.e. the reaction of the tetra-acid chloride with racemic t/zreo-aminotriol will result into a statistical distribution, the probability of formation of all isomers should be identical. These isomers are illustrated schematically in Fig. 20 where the configuration (2R,3S) of the 3-amino-butane-1,2,4-triol is abbreviated as a and 2S,3R) as b . 

BUTANE-1,2,4-TRIOL TRINITRATE ch2ono2-chono2-ch2-ch2ono2... 

Butane-1,2,4-triol trinitrate, also called nitrobutanetriol , is a good solvent of collodion cotton. It is less volatile than nitroglycerine and a chemically stable compound. Its explosive strength is not much inferior to that of nitroglycerine. Its heat of explosion is 1440 kcal/kg [1],... 

BTT and BTN, butane-1,2,4-triol-trinitrate DNT, dinitrotoluene EGDN, ethylene glycol dinitrate HPLC, high-performance liquid chromatography LOD, limits of detection MDQ, minimum detectable quantities NB, nitrobenzene NG, nitroglycerine NN, nitronaphthalene NT, nitrotoluene PETN, pentaerythritol tetranitrate RDX, cyclotrimethylene trinitramine SFE, supercritical fluid extraction SGC, solvating gas chromatography TDM, thermal desorption modulator TNB, trinitrobenzene and TNT, trinitrotoluene. 

Thermodynamic vs. Kinetic Control in the Formation of Isopropylidene Acetals from Butane-1,2,4-triols and Propane-1,2,3-triols... 

Reaction of butane-1,2,4-triol 28 1 with acetone and p-toluenesulfonic acid as catalyst for 62 h gives a thermodynamic mixture of isopropylidene derivatives consisting of the dioxolane 28.2 (90%) and the dioxane 283 (10%) in a com-... 

More sterically demanding ketones can influence the selectivity of dioxolane formation. For example, butane-1,2,4-triol reacts with 3-pentanone43 44 or 3,3-dimethoxypentane45 46 to give a mixture of the dioxolane 2SA and dioxane 28 5 in a ratio of 45 1 respectively [Scheme 3.28]. Enhanced preference for the dioxolane isomer is also observed in the reaction of 2-0-p-methoxybenzyl-t-threitol (29 1) with 3-pentanone [Scheme 3.29].47 48... 

Benzylidenation of (/ )-butane-1,2,4-triol using either benzaldehyde (with azeotropic removal of water) or acetal exchange with benzaldehyde dimethyl acetal gave essentially the same result a mixture of three acetals in the ratio 90 5 5. 

BTTN Butane-1,2,4-triol trinitrate 1 O2NOH2C—CH—CH2—CH2ONO2... 

The same applies to propanc-1,2-diol dinitrale (II) and butane-1.2 4 triol trinitrate (III). They also examined NMR spectra of nitrate esters — their conclusions arc reported in the paragraph on NMR of nitrate esters (p. 284). 

Cyclodehydration of butane-1,2,4-triol to 3-hydroxytetrahydrofurane was accomplished by heating the triol with tosic acid under a column set for vacuum... 

The above kinetically controlled regioselectivity is also reflected in the selective monosilylation of butane-1,2,4-triol. In this case, the sole product obtained is 4-r-butyldimethylsiloxy-butane-l,2-diol with 99% yield (eq 28). The authors rationalized that, with the bulky TBDMSCl, the dibutylstannylene acetal rapidly migrates between the 1,2-diol and 1,3-diols and affords the product of kinetic control. This sequence of reactions was also used to selectively block the equatorial alcohol of a cw-diol on the pyranoside ring... 

Methyl a-o-fucopyranoside reacted with trityl chloride in pyridine to give the 2- and 3-O-trityl derivatives (ratio 3 2) in good yield. A report describing the use of insoluble polymers containing pendant trityl chloride residues to block one of the primary hydroxy-groups of polyhydric alcohols (e.g. butane-1,2,4-triol) is of interest. ... 

ICang and Kim have synthesized both (+ )-239 and ( + )-6>epicastanospennine (240) by yet another modification of the methodology previously seen in their syntheses of slaSnmine and swainsonine (cf. Schemes 6,28) 214). In this case, Wittig reaction between the mixture of 1,3-dioxolan- and 1,3-dioxan-containing aldehydes 44 and 45 [prepared fiximp-anisaldehyde and (S)-butane-l,2,4-triol] and the phosphorus ylide 278 (also derived fixim butane-1,2,4-triol) gave the cir-alkene 279 in 59% yield after selective deprotection and separation fiom unwanted isomers (Scheme 38). The... 

There are subtle reactivity differences between dioxanes and dioxolanes that may be exploited in complex molecule synthesis. This can be of considerable use in the selective removal of these acetal protecting groups under oxidative conditions. A classic example is to be found in Stork s innovative synthesis of erythronolide A (Scheme 6.11) (36). Selective oxidation of 56 with ozone leads to cleavage of the dioxolane in preference to the dioxane to furnish 57. The selectivity is associated with the stereoelectronic effects (LPo<- C-H) that render the dioxolane C-H more labile. The structural differences between dioxolanes and dioxanes can also be used to gain access to protected butane-1,2,4-triol derivatives, as shown on the right [7, 9]. Thus, either 1,2- or 1,3-diols can be selectively masked as the corresponding dioxolane or dioxane, respectively, by selection of acetone or benzaldehyde as the reacting partner. 

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