[2 + 2] Cycloaddition Reactions of 1-Trifluoroacetyl-2-chloroacetylene with Vinyl Ethers

Synthesis of ethyl 4-chloro-2-oxobut-3-ynoate and its addition to alkyl vinyl ethers

“…1,2 Earlier, we have synthesized 1 halo 2 (trifluoroacetyl)acetylenes and studied their reactions with various dienes, 3 alkenes, 4 and vinyl ethers. 5 Acety lenes activated by the alkoxyoxalyl group are studied little despite the unique opportunities, which are provid ed by such a type of functionalization. [6][7][8][9] In particular, there is no information on 4 chloro 2 oxobut 3 ynoates, which can be expected to have high activity in cycloaddi tion reactions and ability to substitute the halogen atom for various nucleophiles.…”