Sucralose and Acesulfame potassium

Artificial sweeteners,  especially aspartame, have hit the news headlines once again with PepsiCo's decision to start selling Diet Pepsi without aspartame from August 2015 in the USA. The aspartame is to be replaced by a blend of sucralose and acesulfame potassium.

Sucralose was discovered in 1976 when Shashikant Phadnis at Queen Elizabeth College was asked to "test" a chlorinated sugar compound but he thought he'd been asked to "taste" it, so he did, and found it be very sweet! Sucralose, shown on the right, is synthesised from sucrose in a number of steps in which 3 of sucrose's hydroxyl groups are substituted for chlorine atoms.
Although sucralose is about 300 times sweeter than sucrose, it is not broken down during digestion and therefore does not contribute to ingested calories (kilojoules).
Splenda is a brand name for a common sucralose-based sweetener.


Acesulfame potassium was accidentally discovered in 1967 by German chemist Karl Clauss, who found it to be sweeter than sucrose. It is not as sweet as sucralose, however, and is often used in combination with other artificial sweeteners such as aspartame or sucralose. It has the structural formula shown below:

Acesulfame potassium is currently sold under the brand names Sunette, Sweet One and Sweet 'n Safe and is found in many "sugar-free" foods such as chewing gum, jelly (Jell-O), even in alcoholic drinks.

Reference:
http://www.smh.com.au/business/retail/diet-pepsi-dumps-aspartame-as-consumer-backlash-hurts-sales-20150425-1msz1b.html

Further Reading:

• http://www.ausetute.com.au/sugars.html 
• http://www.ausetute.com.au/proteins.html
• http://www.ausetute.com.au/fungroup.html
• http://www.ausetute.com.au/intermof.html
• http://www.ausetute.com.au/skeletal.html
• http://www.ausetute.com.au/structural2D.html
• http://www.ausetute.com.au/condensedsf.html
• http://www.ausetute.com.au/molecularformula.html

Suggested Study Questions:

1. What is the molecular formula for:
   • sucralose
   • sucrose
   • acesulfame potassium
2. Draw the structural formula for sucrose and circle the hydroxyl functional groups.
3. Draw the structural formula for sucralose and
   • circle the hydroxyl functional groups in red
   • circle the halogen functional groups in green
   • circle any other functional groups blue and name them 
4. What class of compounds does sucrose belong to?
5. Draw the structural formula for acesulfame potassium and identify the functional groups.
6. Is it appropriate to call acesulfame potassium a potassium salt? Explain your answer.
7. Aspartame is the methyl ester of a didpeptide. What functional groups do you expect the aspartame molecule to have? Explain your answer. 
8. Do you expect sucralose and acesulfame potassium to be soluble in water? Explain your answer.