40646-47-7

Upstream product

• 40646-44-4 3,5,5-trichloro-2-methyl-4-penten-2-ol 
• 937-14-4 3-chloro-benzenecarboperoxoic acid 
• 55667-43-1 1,1-dichloro-4-methyl-penta-1,3-diene 
• 76-03-9 trichloroacetic acid 
• 1552-26-7 5,5,5-trichloro-pent-3-en-2-one 

Relevant academic research and scientific papers

CONVENIENT SYNTHESIS OF 4-(2,2-DICHLOROETHENYL)-5,5-DIMETHYLTETRAHYDRO-2-FURANONE DERIVATIVES, A KEY INTERMEDIATE OF PERMETHRINIC ACID.

A key intermediate of 2-(2,2-dichloroethenyl)-3,3-dimethylcyclopropanecarboxylic acid, 3-alkoxycarbonyl-(or acyl)-4-(2,2-dichloroethenyl)-5,5-dimethyltetrahydro-2-furanone was prepared by the base-catalyzed condensation of 2-methyl-3,5,5-trichloro-4-penten-2-ol with acetate derivatives such as malonic esters, acetoacetic esters, and benzoylacetate. The reactivity of 3-acetyl-4-(2,2-dichloroethenyl)-5,5-dimethyltetrahydro-2-furanone to an excess amount of thionyl chloride in ethanol was also examined. An analog, -butyl-4-(2,2-dichloroethenyl)-3-ethoxycarbonyl-5-methyltetrahydro-2 -furanone was also prepared in 31% yield.

(2,2-Disubstituted vinyl)γ-butyrolactones

(2,2-Disubstituted vinyl)-γ-butyrolactones of the formula: STR1 in which R1 and R2 are hydrogen or C1 -C6 alkyl, preferably methyl, R3 and R4 are hydrogen, C1 -C6 alkyl, preferably methyl, or halogen, or, together with the carbon atom to which they are attached, form a cycloalkyl group, and R5 is C1 -C6 alkyl, are prepared by condensing an epoxide of the formula: STR2 with a malonic acid ester of the formula: STR3 in a basic medium. The butyrolactones of formula I are valuable intermediates for the synthesis of synthetic pyrethroids having insecticidal activity.