An Approach to the Synthesis of 1‑Propenylnaphthols and 3‑Arylnaphtho[2,1‑b]furans

• Published in: Journal of organic chemistry Vol. 82; no. 5; pp. 2523 - 2534
• Main Authors: Huang, Jin, Wang, Wei, He, Hai-Yu, Jian, Lei, Fu, Hai-Yan, Zheng, Xue-Li, Chen, Hua, Li, Rui-Xiang
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 03.03.2017; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; cis-trans isomers; cyclization reactions; dimethylformamide; ethers; furans; isomerization; organic chemistry; oxidants; Physical Sciences; potassium carbonate; Science & Technology; solvents; stereoselectivity; NAPHTHOLS; FACILE SYNTHESIS; REAGENTS; RING-CLOSING METATHESIS; PHENOLS; 2-NAPHTHOLS; OXIDATIVE CYCLIZATION; BENZOFURANS; CLAISEN REARRANGEMENT
• ISSN: 0022-3263; 1520-6904; 1520-6904
• DOI: 10.1021/acs.joc.6b02902

A simple and efficient strategy for the synthesis of 1-propenylnaphthols from readily accessible 3-arylallylnaphthyl ethers has been developed. By using K2CO3 as base and 2-methoxyethanol as solvent, direct access to a wide range of 1-propenylnaphthols can be achieved in generally good yield (up to 99%) with high stereoselectivity toward the Z isomer. The control experiments indicate that the reaction proceeds through a sequential Claisen rearrangement/isomerization process. Furthermore, starting from the same material, the highly valuable 3-arylnaphtho­[2,1-b]­furans can be obtained in N,N-dimethylformamide and in the presence of Ag2O as the oxidant via a one-pot sequential Claisen rearrangement/isomerization/cyclization reaction. Mechanistic studies confirm that 1-propenylnaphthols are the key intermediates to form the 3-arylnaphtho­[2,1-b]­furans. In addition, these two operationally simple and practical protocols could be scaled up to a gram level.