Erythro-l,2-diols

Erythro-l,2-diols. Hydroboration 0 by regioselective ring cleavage affords the... 

Bacillus polymyxa in a hydrogen atmosphere reduced (R,S)-acetoin to erythro- and /Areo-butane-l,3-diol in 100% yield [910], and Saccharomyces cerevisiae converted 3,3-dimethyl-l-hydroxybutan-2-one to (—)-R-3,3-dimethylbutane-l,2-diol in 66% yield [911]. 

Dihydromuscimol (49) is a conformationally restricted analogue of the physiologically important neurotransmitter y-aminobutyric acid (GABA) and has been prepared using the cycloaddition of dibromoformaldoxime to A-Boc-allylamine followed by N-deprotection with sodium hydroxide (Scheme 6.52) (278). The individual enantiomers of dihydromuscimol were obtained by reaction of the bromonitrile oxide with (5)-( + )-l,2-0-isopropylidene-3-butene-l,2-diol, followed by separation of the diastereoisomeric mixture (erythro/threo 76 24), hydrolysis of respective isomers, and transformation of the glycol moiety into an amino group (279). 

The mechanism of cleavage by periodate is consistent with a cyclic, five-membeied ring intermediate (10) shown in Scheme 6. Support comes from the fact that the cis isomers of cyclic diols are more reactive than the trans isomers, t/ireo-l,2-diols undergo oxidation faster than the erythro isomers and the inert behavior of diaxial fra j-l,2-diols which cannot form a cyclic periodate ester. ... 

Chromium (II) chloride)trimethyIsilyI iodide erythro G yco monoethers from acetals and aldehydes 3-Ene-l,2-diol 2-monoethers... 

Decomposition of ketosamines starts, like most other reactions of monosaccharides, by 1,2-enoKsation that yields an amino analogue of l-ene-l,2-diol, which is l-ene-l-amino-2-ol (Figure 4.86). The reaction proceeds by elimination of the C-3 hydroxyl group and hydrolysis of the bound amino compound provides 3-deoxy-o-erythro-hexos-2-ulose and, further, 3,4-dideoxy-D-g/ycero-hex-3-enos-2-ulose, 5-hydroxymethylfuran-2-carbaldehyde in addition to other products that are formed by degradation of glucose by... 

Nuclear Overhauser effects have been used to distinguish threo- and erythro-forms of a-glycols such as l-methylcyclodecane-l,2-diol. ... 

The milder metal hydnde reagents are also used in stereoselective reductions Inclusion complexes of amine-borane reagent with cyclodexnins reduce ketones to opucally active alcohols, sometimes in modest enantiomeric excess [59] (equation 48). Diisobutylaluminum hydride modified by zmc bromide-MMA. A -tetra-methylethylenediamme (TMEDA) reduces a,a-difluoro-[i-hydroxy ketones to give predominantly erythro-2,2-difluoro-l,3-diols [60] (equation 49). The three isomers are formed on reduction with aluminum isopropoxide... 

Compounds similar to glycerol, called sphingoids, are derivatives of sphinganine (o-erj t/iro-2-aminooctadecane-l,3-diol). The trivial name sphinganine implies the stereochemistry the use of the stereodescriptor D-erythro in the systematic name is to be noted. 

Nitrogen-coordinated pentacoordinate complexes have been used as stereoselective reducing agents in the preparation of erythro-(meso)- 1,2-diols from diketones and a-hydroxyketones109. The reducing agent was the (l-naphthylamino-8)trihydridosilane 92e. After formation of the dioxo chelate from the diketone (equation 32), the diol was obtained from the pentacoordinate silicon complex by reduction with LiAlILt. 29 Si NMR spectroscopy was used for the product-ratio analysis in this reaction, which was found to yield primarily the erythro diols. 

The backbone structure of the sphingolipids found in mammalian cells is the long-chain base, sphingosine. The latter is an 18-carbon moiety comprised of an aminoethanol residue at C-l (OH) and C-2 (NH2) with an allylic hydroxyl at C-3. Another name for sphingosine is D-erythro-2-amino-octadec-4-ene-l,3-diol. The latter compound is often referred to as sphingenine by many investigators. 

DL-erythro(threo)-2-amino-4-trans(cis)-decene-l,3-diol 38... 

Ibata s group extensively investigated [3 + 2] cycloaddition reactions of 5-alkoxyoxazoles with aldehydes as a means of preparing precursors of p-hydroxy amino acids or 2-amino-l,3-diols. In particular, acid hydrolysis of cw-2-oxazoline-4-carboxylates produces the relatively inaccessible erythro-p-hydroxy amino acids. The authors studied the effects of solvent, temperature, Lewis acid, and aldehyde substituent on the product distribution and developed a synthesis of 2-oxazoline-4-carboxylates that is both cii-selective and enantioselective. 

The stereochemistry at the chiral centres of the three new lignans, erythro-strebluslignanol, threo-T-methoxyl strebluslignanol and erythro-T-meth-oxyl strebluslignanol has been established by Li et al by analysis of vicinal proton-proton couplings as well as CD spectra and optical rotation data. The determined chemical structures of these compounds were (7 R,8 5)-5-allyl-5 -(l,2-dihydroxypropyl)[l,l -biphenyl]-2,2 -diol, (7 R,8 R)-5-allyl-5 -(2-hydroxy-l-methoxypropyl)[l,l-biphenyl]-2,2 -diol and (7 R,8 5)-5-allyl-5 -(2-hydroxy-l-methoxypropyl)[l,l-biphenyl]-2,2 -diol. 

Form Supplied in white solid widely available normally supplied as the racemate, but chiral 1,4-dithio-L-threitol 97-2, mp 49-51 °C, is also available. The erythro isomer (1,4-dithioerjfthritol, DTE, [6892 68-8, mp 82-84 °C) has redox properties similar to the threo isomer [E7 is more positive by 0.004 V) and is also available. The oxidized cyclic form (frans-l,2-dithiane-4,5-diol [14193-38-5], mp 130-132 °C) is available it has a UV spectrum (kmax 283 nm s = 273). DTT and DTE are colorless above 260 nm, but both reduced and oxidized forms absorb below 240 nm. 

CYCLOBUTANE, l-BROMO-3-CHLORO-, 51,106 Cyclobutanecarbonyl chloride, reaction with erythro- 2,3-butane-diol monomesylate, 51,12 CYCLOBUTANECARBOXALDE-HYDE, 51,11... 

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