Old rose

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Structural formula
Structure of old rose
Fischer projection , open-chain representation
General
Surname D - (+) - old rose, L - (-) - old rose
other names
  • (2 S , 3 R , 4 R , 5 R ) -pentahydroxyhexanal
  • (2 R , 3 S , 4 S , 5 S ) -pentahydroxyhexanal
Molecular formula C 6 H 12 O 6
Brief description

white solid

External identifiers / databases
CAS number
  • 1990-29-0 ( D -Altrose)
  • 1949-88-8 ( L -Altrose)
EC number 217-870-4
ECHA InfoCard 100.016.247
PubChem 94780
ChemSpider 85516
Wikidata Q423207
properties
Molar mass 180.16 g mol −1
Physical state

firmly

Melting point

106-108 ° C

safety instructions
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Altrose is a monosaccharide with six carbon atoms. This sugar belongs to the group of non-naturally occurring aldohexoses with the molecular formula C 6 H 12 O 6 .

As with any sugar (except for dihydroxyacetone) there are two enantiomeric forms that behave like an image and a mirror image. When "Altrose" is mentioned in this text or in the scientific literature without any additional name ( prefix ), D- Altrose is meant.

properties

In aqueous solution, an intramolecular ring closure sometimes occurs, so that an equilibrium is established between the aldehyde form and the two ring forms ( furanose and pyranose ):

D -Altrose - spellings
Wedge formula Haworth notation
D-Altrose Keilstrich.svg Alpha-D-altrofuranose.svg
α- D -Altrofuranose
20% 		Beta-D-altrofuranose.svg
β- D -Altrofuranose
13%
Alpha-D-Altropyranosis.svg
α- D -Altropyranose
27% 		Beta-D-Altropyranosis.svg
β- D -Altropyranose
40%

proof

Fehling's reaction

The detection of the aldehyde group in an aqueous solution of a mixture of copper (II) sulfate (Fehling I) and basic potassium-sodium-tartrate solution (Fehling II) is positive, solid copper (I) oxide (brick-red) is formed Precipitation) (see Fehling's sample ).

Tollens reaction (silver mirror sample)

The Ag + ion in silver nitrate solution is reduced to elemental silver by the old rose , which ideally covers the test vessel with a metal mirror (see Tollens sample ).

Individual evidence

  1. ↑ a b Data sheet D - (+) - Altrose at Acros, accessed on February 19, 2010.
  2. ↑ Data sheet L - (-) - Altrose at Acros, accessed on February 19, 2010.
  3. ↑ a b Data sheet D-Altrose, ≥97.0% (HPLC) from Sigma-Aldrich , accessed on February 5, 2013 ( PDF ).
  4. ↑ a b Data sheet L-Altrose, ≥97.0% (HPLC) from Sigma-Aldrich , accessed on February 5, 2013 ( PDF ).
  5. ↑ Jürg Hunziker: Carbohydrate Chemistry ( Memento from May 10, 2008 in the Internet Archive ), April 1, 2007.

Web links

Commons : Altrose  - collection of images, videos and audio files