Cinchonidine-Catalyzed Synthesis of Oxazabicyclo[4.2.1]nonanones from N-Aryl-α,β-unsaturated Nitrones and 1-Ethynylnaphthalen-2-ols was written by Wei, Cui;Zhou, Zhou;Pang, Guang-Li;Liang, Cui;Mo, Dong-Liang. And the article was included in Organic Letters in 2022.Synthetic Route of C6H4S This article mentions the following:
A variety of oxazabicyclo[4.2.1]nonanone derivatives, I (R = Ph, naphthalen-2-yl, thiophen-3-yl, pyridin-3-yl, etc., R1 = Ph, 4-Cl-3-FC6H3, furan-2-yl, pyridin-2-yl, etc., R2 = H, PhCC, R3 = H, Br, Ar = Ph, 4-F3CC6H4, 3,5-Me2C6H3, naphthalen-2-yl, etc.), was prepared in good yields through a cinchonidine-catalyzed cascade reaction of N-aryl-α,β-unsaturated nitrones R1CH=CHCH=N(O)Ar and 1-ethynylnaphthalen-2-ols II. Mechanistic studies show that the reaction undergoes a [4+3]-cycloaddition of nitrones to the vinylidene o-quinone methide generated in situ from the 1-ethynylnaphthalen-2-ols in the presence of cinchonidine, 1,3-rearrangement of N-O vinyl moieties, ring-opening, and finally double intramol. cyclizations to afford oxazabicyclo[4.2.1]nonanones I over five steps in a one-pot reaction. In the experiment, the researchers used many compounds, for example, 3-Ethynylthiophene (cas: 67237-53-0Synthetic Route of C6H4S).
3-Ethynylthiophene (cas: 67237-53-0) belongs to benzothiophene derivatives. Benzothiophene is relatively a stable molecule. The core structure is a part of various pharmaceutical substances and natural products. It is found within the chemical structures of pharmaceutical drugs such as raloxifene, zileuton, sertaconazole, and also BTCP.Synthetic Route of C6H4S
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem