Direct Heterocyclization of Benzocrown Ethers.

Abstract

Multi-membered O,S-heterocycles R 0691Direct Heterocyclization of Benzocrown Ethers. -Novel crown ether derivatives fused to 3,4-dihydroisoquinoline are synthesized via reaction of benzocrown ethers (I) with aldehydes and cyanide derivatives. -(SHKLYAEV, Y. V.; GORBUNOV, A. A.; ROZHKOVA, Y. S.; VSHIVKOVA, T. S.; VAZHENIN, V. V.; MAIOROVA, O. A.; TOLSTIKOV, A. G.; DEMBITSKY*, V. M.; Heteroat. Chem. 16 (2005) 3, 192-195; Dep. Org. Chem., Hebrew Univ., Jerusalem 91904, Israel; Eng.) -H. Toeppel 37-167

Retropinacol rearrangement in the synthesis of 3,3,4-trimethyl-3,4-dihydroisoquinoline derivatives

“…We previously reported [1][2][3] that isobutyraldehyde, 2-ethylhexanal, and cyclohexanecarbaldehyde react with activated arenes and nitriles in concentrated sulfuric acid to give 3,3-dialkyl-3,4-dihydroisoquinoline derivatives. It is also known that 3,3,4,4-tetramethyl-3,4-dihydroisoquinoline derivatives exhibiting a broad spectrum of biological activity [4] can be synthesized via retropinacol rearrangement of 3,3-dimethyl-2-phenylbutan-2-ol [5].…”