L-Sorbose
HO
Product Code: MS05200
CAS Number: 87-79-6
Chemical Formula: C 6 H 12 O 6
Molecular Weight: 180.16
OH
O
HO
OH
OH
L-Sorbose belongs to the L-series of natural sugars and has a sweetness equivalent to sucrose.
L-Sorbose exists in equilibrium between its open keto form and any of two pyranose and two
furanose forms (Fig. 1). There have been reported contrasting studies leading to some debate
about its relative adoption of these forms5. Control of the conditions allows manipulation of the
thermodynamic and kinetic stabilities of these conformers to give a number of useful synthetic
building blocks.
HO
HO
OH
O
HO
O
HO
OH
O
HO
HO
OH
OH
OH
HO
OH
OH
OH
Figure 1
L-Sorbose is produced from D-Sorbitol by Gluconobacter oxydans or Acetobacter species via
regiocontrolled dehydrogenation. This microbial oxidation is employed during the Reichstein1
process for the production of vitamin C (Fig. 2)where the L-sorbose provides the necessary
stereochemistry for further chemical synthesis.
OH
OH
HO
[O]
HO
O
HO
OH
OH
D-sorbitol
O
O
b-L-sorbopyranose
O
O
OH
O
O
O
[O]
OH
O
H+, Acetone
OH
OH
OH
OH
HO
O
O
O
O
O
HO
H2O
OH OH
L-Ascorbic acid
Figure 2
From this process the protection of L-Sorbose with Acetone provides a useful building block for
chemical synthesis, leaving the 1-hydroxy group free for functionalisation via alkylation or
esterification (Fig. 3). The hydroxyl group can also be oxidised to an aldehyde, granting access
to approaches such as Wittig or Baylis Hillman. Hence, this useful intermediate has been
employed in a number of total syntheses6. Further oxidation to the carboxylic acid allows the
formation of amides7 and esters8.
Carbosynth Limited
8&9 Old Station Business ParkCarbosynth
- ComptonLimited
- Berkshire - RG20 6NE - UK
8&9 Old
Station Business Park - Compton
- Berkshire
- RG20
UK 579444
www.carbosynth.com
[email protected]
Tel: +44 1635
578444
Fax: 6NE
+44 -1635
www.carbosynth.com [email protected] Tel: +44 1635 578444 Fax: +44 1635 579444
O
O
O
O
O
[O]
OH
O
O
O
O
O
O
O
Baylis Hillman
Wittig
O
OR
O
O
O
O
O
O
O
O
R
O
HO
O
O
O
O
R
O
O
HO
O
O
O
O
O
O
O
[O]
O
O
O
R=alkyl or COR'
RX
X=O or N
Figure 3
The open form of L-Sorbose has been converted to an imidazole derivative which was found to
have an inhibitory effect in a number of glycoprocesses9 (Fig. 4).
HO
HO
O
HO
N
HO
OH
HO
HO
NH
OH
OH
Figure 4
L-sorbose is also used as a precursor for the synthesis of other rare sugars such as L-tagatose2
and L-iditol3. L-Sorbose has also been applied to microbial culture media where it has been
observed to alter the growth rate of fungi4.
References:
1. T. Reichstein, A. Grussner, and R. Oppenauer. Helv. Chem. Acta 1933, 311-328
2. H. Itoh, K. Izumori, J. Ferment. Bioeng., 1996, 351-353
3. M. Ogawa et al, Appl. Environ. Microbiol., 1983, 912-916
4. D. K . Sahoo et al, J. General Microbiology, 1986, 2761-2766
5. A. S. Perlin, C. Brice, Can. J. Chem., 1956, 541-553
Carbosynth Limited
8&9 Old Station Business ParkCarbosynth
- ComptonLimited
- Berkshire - RG20 6NE - UK
8&9 Old
Station Business Park - Compton
- Berkshire
- RG20
UK 579444
www.carbosynth.com
[email protected]
Tel: +44 1635
578444
Fax: 6NE
+44 -1635
www.carbosynth.com [email protected] Tel: +44 1635 578444 Fax: +44 1635 579444