How to Synthesize Ribose
The Swern oxidation-reduction method is of ribose synthesis is a practical and very affective way to perform. When the process is carried out correctly there is a significant high increase percentage in efficiency. Here is how to properly synthesize ribose.
Materials Needed:
- L-arabinose
- 16.4 g, 100 millimolar methyl beta-L-arabinopyranoside
- 38.6 g, 300 millimolar 2,2-dimethoxypropane
- 130 milliliters of dry dimethyl formamide
- Amberlyst 15, 1 g
- Mechanical stirrer
- Dimethyl sulfoxide (DMSO)
- Oxalyl chloride
- Reducing agent such as LiAlH4
- EtOH
- 80 percent AcOH
- Methyl beta-L-ribopyranoside
- Silica gel column chromatography apparatus
- Bunsen burner
- Beaker
- Create a pure colorless syrup from L-arabinose. The syrup should be created from L-arabinose derivative, 3, 4-O-isoprpylidene-beta-L-abarbinoside. Mix together 16.4 g, 100 millimolar methyl beta-L-arabinopyranoside with 38.6 g, 300 millimolar 2,2-dimethoxypropane in 130 milliliters of dry dimethyl formamide. Make sure you do it in the presence of Amberlyst 15, 1 g. Stir this mechanically for 18 hours at room temperature. Filter the resin when the stirring is done and evaporate the solvent, and then use m-xylene to co-evaporate the solvent. This product will form into a syrup-like form of L- arabinose.
- Subject the L-arabinose product to Swern oxidation. This is a chemical procedure that is used to avoid toxic metals usage. Create Dimethylchlorosulphonium ion by reacting DMSO with oxalyl chloride at -78 degrees Celsius. This is then de- protonated and forms a sulphur ylide.
- Follow the reduction with an effective reducing agent present, such as LiAH4. Be sure to use it in EtOH at zero degrees Celsius.
- Add a compound to 80 percent AcOH, methyl beta-L- ribopyranoside to de-protect the isopropylidene group of derivative. Make sure to shake off the excess, unwanted groups. To do this, subject the resulting mixture to silica gel column chromatography.
- Take the resulting mixture and repeat the Swern oxidation, reduction and de-protection process. This will further improve the mid-stage yield. Once you get the final compound, de-protect the anomeric position of it by treating it with 0.8 molar HCI.
- Create the final required product, L-ribose by neutralizing the reaction mixture with an acid catalyst in hydrogen ion (H+).