Lollipops are a favorite candy around my house. My kids really like the little ones called Dum-dums.
I can't eat them unless it is just pure sugar, not any of the new extracted sugars. I miss them. 
What do you mean by extracted sugars? What are some examples?
Oh, the compounded sugars like Trehalose Trehalose.svg Trehalose-from-xtal-2008-CM-3D-balls.png Trehalose-from-xtal-2008-CM-3D-SF.png Names IUPAC name (2R,3S,4S,5R,6R)-2-(Hydroxymethyl)-6-[(2R,3R,4S,5S,6R)-3,4, 5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyoxane-3,4,5-triol Other names α,α‐Trehalose; α-D-glucopyranosyl-(1→1)-α-D-glucopyranoside Identifiers CAS Number 99-20-7 (anhydrous) Yes 6138-23-4 (dihydrate)  3D model (JSmol) Interactive image ChEBI	 CHEBI:16551 Yes ChEMBL	 ChEMBL1236395  ChemSpider	 7149 Yes ECHA InfoCard	100.002.490 PubChem CID 7427 UNII	 B8WCK70T7I Yes InChI[show] SMILES[show] Properties Chemical formula C12H22O11 (anhydride) Molar mass	342.296 g/mol (anhydrous) 378.33 g/mol (dihydrate) Appearance	White orthorhombic crystals Density	1.58 g/cm3 at 24 °C Melting point	203 °C (397 °F; 476 K) (anhydrous) 97 °C (dihydrate) Solubility in water 68.9 g per 100 g at 20 °C[1] Solubility	soluble in ethanol, insoluble in diethyl ether and benzene[2] Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).  verify (what is Yes ?) Infobox references Trehalose is a sugar consisting of two molecules of glucose. It is also known as mycose or tremalose. Some bacteria, fungi, plants and invertebrate animals synthesize it as a source of energy, and to survive freezing and lack of water. Problem is, we don't know what products use it!
Wow. That is some detail. When you say you can only eat pure sugar, then, do you mean sucrose? Or does it include others as well?
Yep, oh, sorry about that dang link stuff, I copied too much. I only eat pure sugars when I can. Sometimes you don't know! So I gave up lollipops, bummer! 
I was curious, though, about what you mean when you say pure sugar. Is it sucrose only or does it include other sugars, like those you get when you eat fruit?
Sucrose
Sucrose is common sugar. It is a disaccharide, a molecule composed of two monosaccharides: glucose and fructose. Sucrose is produced naturally in plants, from which table sugar is refined. It has the molecular formula CHO.
For human consumption, sucrose is extracted, and refined, from either sugar cane or sugar beet. Sugar mills are located where sugarcane is grown to crush the cane and produce raw sugar which is shipped around the world for refining into pure sucrose. Some sugar mills also process the raw sugar
will be mostly sugar. Sugar is mostly extracted from plants by juicing them, then drying the purified juice, so "evaporated cane juice crystals" or "concentrated grape juice" are also very similar to pure sugars.
Sugars and sugar products.
- Agave nectar – very high in fructose and sweeter than honey
- Arabinose
- Barbados sugar
- Barley malt syrup, barley malt – around 65% maltose and 30% complex carbohydrate
- Barley sugar – similar to hard caramel
- Beet sugar –