1,3-Dithiane (TCI D0119) is a saturated six-membered heterocycle with two sulfur atoms at positions 1 and 3. It is well known in synthetic organic chemistry for its role in umpolung, the reversal of carbonyl carbon polarity, which Corey and Seebach popularized. When a strong base such as n-butyllithium deprotonates it, the carbon between the two sulfur atoms forms a stable carbanion. This carbanion acts as an acyl anion equivalent and reacts with a wide range of electrophiles, which makes 1,3-dithiane a standard building block in the synthesis laboratory.
Chemists choose this reagent because it gives access to carbon-carbon bonds that are difficult to form with ordinary carbonyl chemistry. After alkylation, or after reaction with aldehydes, ketones, or epoxides, the dithiane group can be hydrolyzed back to a carbonyl. This hydrolysis typically uses mercury salts, hypervalent iodine reagents, or other oxidative methods. Researchers can therefore build ketones, α-hydroxy ketones, and 1,2-dicarbonyl compounds in a controlled way. Dithianes also hold up under many acidic and basic conditions, so they work well as carbonyl protecting groups during multistep sequences.
In Indonesia, 1,3-dithiane matters most to university research groups working on natural product total synthesis, medicinal chemistry, and synthetic methodology. Graduate students and research staff use it to show how polarity reversal opens new disconnections in retrosynthetic planning. It also appears in projects that build functionalized carbonyl intermediates for bioactive target molecules. The reagent is relevant to advanced organic chemistry teaching as well, where the Corey-Seebach reaction is a classic example of carbanion chemistry and protecting group strategy.
- Corey-Seebach umpolung reactions: deprotonation with n-butyllithium forms a stabilized carbanion that serves as an acyl anion equivalent for coupling with electrophiles.
- Ketone synthesis: the lithiated dithiane is alkylated and the dithiane group is then hydrolyzed, which gives ketones that are hard to reach by conventional carbonyl chemistry.
- Preparation of α-hydroxy ketones: the dithiane anion adds to aldehydes or ketones, and later deprotection reveals the carbonyl next to the new hydroxyl group in a controlled way.
- Construction of 1,2-dicarbonyl compounds: sequential functionalization and hydrolysis of the dithiane unit let researchers build adjacent carbonyl groups for complex target molecules.
- Carbonyl protection in multistep synthesis: dithianes are stable under many acidic and basic conditions, so they protect carbonyl groups while other transformations take place elsewhere in the molecule.
| Brand | TCI (product code D0119) |
|---|---|
| CAS number | 505-23-7 |
| Molecular formula | — |
| Purity | — |
| Category | Chemistry > Building Blocks > Heterocyclic Building Blocks |
| Pack sizes | see the available options on the product page |
| Physical form | refer to the TCI product label and Safety Data Sheet |
| Storage | follow the conditions stated on the TCI label and SDS |
Keep 1,3-dithiane in its original tightly closed TCI container in a cool, dry, well-ventilated area, away from strong oxidizing agents, heat, and direct sunlight. Follow the storage conditions on the label and Safety Data Sheet. As a sulfur-containing compound, it may give off an unpleasant odor, so open and weigh it inside a fume hood. Wear safety glasses, chemical-resistant gloves, and a lab coat. When using strong bases such as n-butyllithium for deprotonation, work under an inert atmosphere with dry glassware. Dispose of waste, including mercury-containing hydrolysis residues, according to institutional hazardous waste procedures.
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