Methyl cyclopentenol ketone is an organic compound with a molecular formula of C6H8O2 . Mainly used to prepare maple, smoked, butterscotch and apricot flavors.
Chinese name：甲基环戊烯醇酮
Alias：3-methyl-2-hydroxy-2-cyclopenten-1-one
Chemical formula：C6H8O2
Molecular weight：112.13
CAS Registry Number：80-71-7
Boiling point：242 °C
Density1.2 g/cm³
White to light yellow crystalline powder
Physical properties
[Appearance] White crystalline powder, exposed to the air for a long time, easy to oxidize and gradually turn yellow.
【Melting point】(℃) 104-108
【Flash point】℃ (closed type)
【Density】g/cm31
[Solubility] It is soluble in boiling water, ethanol, acetone, phenylpropanol, ethylene glycol, glycerol and chloroform, and slightly soluble in ether.1 g of MCP can be dissolved in 75 ml of water at room temperature.
【Stability】Easy to sublimate, easy to decompose at high temperature.When exposed to the air for a long time, it will gradually turn yellow if it is easily oxidized.
CAS accession number] 80-71-7 (enol); 765-70-8 (dione)
[EINECS accession number] 201-303-2 (enol); 212-154-8 (dione)
[Molecular formula and structural formula] The molecular formula is C6H8O2, andits structural formula has the following three tautomers, among which the structural formula (1) is more representative.
[Common chemical reaction] Because MCP has both carbonyl and hydroxyl groups of cycloalkene.Therefore, it hasmultiple chemical properties ofolefins,carbonyl groupsand hydroxyl compounds. Itforms a complex withirontrioxide and appears blue-violet. It can participate in esterification, addition, substitution and ring-opening reactions, and is prone to enol tautomerism. Structure.
【Incompatibility】oxidant, strong acid, strong alkali.
[Polymerization hazard] No polymerization hazard.
The main purpose
MCP has good sensory properties and is widely used in cakes,beverages, candies, tobacco, toothpaste and pharmaceutical industries, especially for coffee-type foods andtobacco.China's "Food Additives Hygienic Standards" (GB2760-2003) stipulates that it is permitted to useedible spices.When it is used as afood additive, the executive standard is "Food Additive Methyl Cyclopentenol Ketone" (QB/T2641-2004).Mainly used to prepare maple, smoked, butterscotch and apricot flavors.Generally, it is added in the later stage of production, dissolved in a dilute solution alone or dissolved in other flavors and added to food for use.It can also be used in detergents,cosmeticsand other products.Use limit (mg/kg): soft drinks 11; cold drinks 5.6; candy 18; baked goods 13; puddings 14; gum 8.0-15; syrup 10.That is, the allowable upper limit of methylcyclopentenolone per kilogram of food is 5-18mg.
Production method
There are nearly 20 methods for synthesizing MCP at home and abroad.However, only theisoprenemethod, the oxalate method and the 5-methylfurfuryl alcohol methodhave industrial value.By the use of generaldiethyl glutarateanddiethyl oxalatecondensation by Clay Johnson, methylation and decarboxylation reaction of:
Secondly, in the presence of basic catalysts such as sodium alkoxide, sodium hydride, etc., adipic acid diester first undergoes Dieckman coupling, cyclizes to 2-carbethoxycyclopentanone, and then reacts with methylating reagents. For example, the substitution reactionof methyl iodide, methyl bromide or methyl chloride produces 2-methyl-2-carbomethoxy-cyclopentanone.After the substituted cyclopentanone is purified, it undergoes oxychlorination reaction with chlorine gas to produce 5,5-dichloro-2methyl-2-carbomethoxycyclopentanone, which is finally decarboxylated by acidic hydrolysis to obtain the target product MCP.
[] Chain upstreamisoprene, diethyl oxalate ester, 5-methyl furfural,diethyl glutarate,diethyl adipateand the like.Downstream methyl cyclopentenol ketone, flavors for food and beverages.
[Reference quality index] QB/2641-2004 (in line with American FCC standards)
Packaging and storage
Lined withpolyethylene plasticbag sealed packaging cardboard.Store in a dark, cool, dry and ventilated warehouse, away from fire.Avoid mixed storage, mixed packing, and mixed transportation with strong oxidants, strong acids, and strong bases.
