63406-19-9

Upstream product

• 63142-57-4 ethyl (+/-)-trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate 
• 60066-54-8 ethyl 4-bromo-6,6,6-trichloro-3,3-dimethylhexanoate 
• 63142-59-6 4-(2,2-dichloroethenyl)dihydro-5,5-dimethyl-2(3H)-furanone 
• 65771-92-8 3-methyl-3-chloro-2-(2',2'-dichlorovinyl)-butanecarboxylic acid ethyl ester 
• 7796-72-7 ethyl 3,3-dimethylpent-4-enoate 
• 63435-29-0 ethyl 6,6,6-trichloro-3,3-dimethyl-4-hexenoate 
• 60066-84-4 ethyl 2,2-dimethyl-3-(2,2,2-trichloroethyl)-cyclopropanecarboxylate 

Relevant academic research and scientific papers

A Convenient Synthesis of Ethyl 3-(2,2-Dihaloethenyl)-2,2-dimethylcyclopropanecarboxylates and Its Modifications for cis-Isomer Enrichment

A synthesis of the title compounds 5 involves the reaction between 3-methyl-2-buten-1-ol and triethyl orthoacetate to produce ethyl 3,3-dimethyl-4-pentenoate, which is followed by the addition of various carbon tetrahalides to the double bond.The reaction of resulting adducts with a base affords 5 in high yields.Stereoselective preparation of the cis-isomer was achieved by the following two methods: First one involves selective transformation of ethyl 4-bromo-6,6,6-trichloro-3,3-dimethylhexanoate to ethyl 6,6,6-trichloro-2,3-dimethyl-4-hexanoate (8a) with piperidine followed by the selective conversion of 8a to cis-2,2-dichloroethenyl compound (cis-5a).Second one is based on the stereoselective cyclization of ethyl 4,6,6,6-tetrachloro-3,3-dimethyl-hexanoate (t-BuONa/solvent/HMPA) to ethyl cis-2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate which is transformed into cis-5a without cis-trans isomerisation.