121-20-0

Basic information

• Product Name: 3-(but-2-enyl)-2-methyl-4-oxocyclopent-2-enyl2,2-dimethyl-3-(3-methoxy-2-methyl-3-oxoprop-1-enyl)cyclopropanecarboxylate
• Synonyms: 3-(but-2-enyl)-2-methyl-4-oxocyclopent-2-enyl2,2-dimethyl-3-(3-methoxy-2-methyl-3-oxoprop-1-enyl)cyclopropanecarboxylate;Cyclopropanecarboxylic acid, 3-(1E)-3-methoxy-2-methyl-3-oxo-1-propenyl-2,2-dimethyl-, (1S)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-cyclopenten-1-yl ester, (1R,3R)-;cinerin II 3-(but-2-enyl)-2-methyl-4-oxocyclopent-2-enyl 2,2-dimethyl-3-(3-methoxy-2-methyl-3-oxoprop-1-enyl)cyclopropanecarboxylate;(1R,3R)-3-[(E)-3-Methoxy-2-methyl-3-oxo-1-propenyl]-2,2-dimethylcyclopropanecarboxylic acid (S)-3-[(Z)-2-butenyl]-2-methyl-4-oxo-2-cyclopenten-1-yl;(1R,3R)-3-[(1E)-3-Methoxy-2-Methyl-3-oxo-1-propen-1-yl]-2,2-diMethylcyclopropanecarboxylic Acid (1S)-3-(2Z)-2-Buten-1-yl-2-Methyl-4-oxo-2-cyclopenten-1-yl Ester;Cinerin Ⅱ
• CAS NO: 121-20-0
• Molecular Formula: C₂₁H₂₈O₅
• Molecular Weight: 359.43608
• EINECS: 204-454-2
• Product Categories: Chiral Reagents
• Mol File: 121-20-0.mol
• Article Data: 1

Chemical Properties

• Boiling Point: bp0.001 182-184°
• Flash Point: 195.3°C
• Appearance: /
• Density: 1.12g/cm³
• Vapor Pressure: 2.01E-08mmHg at 25°C
• Refractive Index: nD20 1.5183
• CAS DataBase Reference: 3-(but-2-enyl)-2-methyl-4-oxocyclopent-2-enyl2,2-dimethyl-3-(3-methoxy-2-methyl-3-oxoprop-1-enyl)cyclopropanecarboxylate(CAS DataBase Reference)
• NIST Chemistry Reference: 3-(but-2-enyl)-2-methyl-4-oxocyclopent-2-enyl2,2-dimethyl-3-(3-methoxy-2-methyl-3-oxoprop-1-enyl)cyclopropanecarboxylate(121-20-0)
• EPA Substance Registry System: 3-(but-2-enyl)-2-methyl-4-oxocyclopent-2-enyl2,2-dimethyl-3-(3-methoxy-2-methyl-3-oxoprop-1-enyl)cyclopropanecarboxylate(121-20-0)

Safety Data

• Hazard Codes: Xn,N
• Statements: 22-50/53
• Safety Statements: 60-61
• RIDADR: 2902
• HazardClass: 6.1(b)
• PackingGroup: III
• Hazardous Substances Data: 121-20-0(Hazardous Substances Data)

Usage

Uses

Different sources of media describe the Uses of 121-20-0 differently. You can refer to the following data:
1. An active insecticidal constituent of pyrethrum flowers. Oxidizes rapidly and becomes inactive in presence of air.
2. Insecticide.

InChI:InChI=1/C21H28O5/c1-7-8-9-14-13(3)17(11-16(14)22)26-20(24)18-15(21(18,4)5)10-12(2)19(23)25-6/h7-8,10,15,17-18H,9,11H2,1-6H3/b8-7+,12-10+/t15-,17-,18+/m1/s1

Upstream product

• 97-41-6 ethyl 2,2-dimethyl-3-(2-methylpropenyl)cyclopropanecarboxylate 
• 74-88-4 methyl iodide 
• 3894-82-4 (S,Z)-2-(but-2-en-1-yl)-4-hydroxy-3-methylcyclopent-2-en-1-one 
• 93132-69-5 (1R,3R)-2,2-Dimethyl-3-((E)-2-methyl-3-oxoprop-1-en-1-yl)cyclopropane-1-carboxylic Acid 
• 35867-05-1 methyl (1R)-trans-2,2-dimethyl-3-[(E)-2-methyl-3-oxo-1-propenyl]cyclopropanecarboxylate 
• 77087-34-4 (S)-4-hydroxy-3-methyl-2-(2-propynyl)-cyclopent-2-ene-1-one 
• 4638-92-0 (1R,3R)-trans-chrysanthemic acid 
• 827-90-7 trans-chrysanthemic acid 
• 97-41-6 ethyl trans-(+/-)-chrysanthemate 
• 27335-33-7 methyl (1R,3R)-3-formyl-2,2-dimethylcyclopropanecarboxylate 

Relevant articles and documents

Total Syntheses of All Six Chiral Natural Pyrethrins: Accurate Determination of the Physical Properties, Their Insecticidal Activities, and Evaluation of Synthetic Methods

Chiral total syntheses of all six insecticidal natural pyrethrins (three pyrethrin I and three pyrethrin II compounds) contained in the chrysanthemum (pyrethrum) flower were performed. Three common alcohol components [(S)-cinerolone, (S)-jasmololone, and (S)-pyrethrolone] were synthesized: (i) straightforward Sonogashira-type cross-couplings using available (S)-4-hydroxy-3-methyl-2-(2-propynyl)cyclopent-2-en-1-ones (the prallethrin alcohol) for (S)-cinerolone (overall 52% yield, 98% ee) and (S)-pyrethrolone (overall 54% yield, 98% ee) and (ii) traditional decarboxylative-aldol condensation and lipase-catalyzed optical resolution for (S)-jasmololone (overall 16% yield, 96% ee). Two counter acid segments [(1R,3R)-chrysanthemic acid (A) and (1R,3R)-second chrysanthemic acid precursor (B)] were prepared: (i) C(1) epimerization of ethyl (±)-chrysanthemates and optical resolution using (S)-naphthylethylamine to afford A (96% ee) and (ii) concise derivatization of A to B (96% ee). All six pyrethrin esters (cinerin I/II, jasmolin I/II, and pyrethrin I/II) were successfully synthesized utilizing an accessible esterification reagent (TsCl/N-methylimidazole). To investigate the stereostructure-activity relationship, all four chiral stereoisomers of cinerin I were synthesized. Three alternative syntheses of (±)-jasmololone were investigated (methods utilizing Piancatelli rearrangement, furan transformation, and 1-nitropropene transformation). Insecticidal activity assay (KD50 and IC50) against the common mosquito (Culex pipiens pallens) revealed that (i) pyrethrin I > pyrethrin II, (ii) pyrethrin I (II) > cinerin I (II) ? jasmolin I (II), and (iii) "natural" cinerin I ? three "unnatural" cinerin I compounds (apparent chiral discrimination).