Phase transfer catalyzed (PTC) reactions of chloroform with alkenyl carboxylates. Effect of catalyst structure on reaction course

✍ Scribed by Michał Fedoryński; Magdalena Kubicka-Prusik; Małgorzata Kursa; Andrzej Jończyk

• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 595 KB
• Volume: 53
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(96)01029-0

✦ Synopsis

ReactIon of chloroform wth ketone enol esters Id,e carried out in the presence of 50% aq NaOH and benzyltrlethylammomum chloride (TEBAC) as a catalyst gives ,qem-dnzhlorocyclopropanes 3d,e In the case of enol esters of aldehydes, adducts of trlchloromethyl anion 2a,b,f,b (from la,b,f,h)

or mixtures of 2 and 3 (from lc,g,i) are formed The same reaction carried out with a catalytic amount of tetramethylammon~um hydrogen sulphate (TMAHS) yields mixtures of 2 and 3, highly enrrched m the latter products, or pure 3i from Ii. The kmd of the products formed depends on ease of cleavage of 1 by base, nucleophiliclty of carbon-carbon double bond m 1, and type of the catalyst apphed.