Iodo- and bromo-enolcyclization of 2-(2-propenyl)cyclohexanediones and 2-(2-propenyl)cyclohexenone derivatives using iodine in methanol and pyridinium hydrobromide perbromide in dichloromethane
Iodo- and bromo-enolcyclization of 2-(2-propenyl)cyclohexanediones and 2-(2-propenyl)cyclohexenone derivatives using iodine in methanol and pyridinium hydrobromide perbromide in dichloromethane
作者:Malose J. Mphahlele、Thwanthwadi B. Moekwa
DOI:10.1039/b505491e
日期:——
α-Allylcyclohexane-1,3-diones undergo one-pot iodine–methanol promoted iodocyclization and oxidative aromatization to afford variously substituted 2-iodomethyltetrahydrobenzofuran-4-ones (minor) and 2-iodomethyl-4-methoxydihydrobenzofuran derivatives (major). On the other hand, the α-allyl-1,3-cyclohexanediones react with pyridinium hydrobromide perbromide in dichloromethane to afford mixtures of 2-bromomethyltetrahydrobenzofuran-4-ones (major) and 3-bromomethyltetrahydrobenzopyran-5-ones (minor). The prepared products and their derivatives were characterized using a combination of NMR, FT-IR and mass spectroscopic techniques.
Synthesis and chemical transformation of fused tetrazoles derived from 2-bromomethyl- and 2-iodomethyl-3,5,6,7-tetrahydro-4(2<i>H</i>)-benzofuranones
作者:Malose J. Mphahlele、Thwanthwadi B. Moekwa
DOI:10.1002/jhet.5570430414
日期:2006.7
The 2-bromomethyl-3,5,6,7-tetrahydrobenzofuranones 1a-d were subjected to triazidochlorosilanesodium azide-mediated Schmidt rearrangement to afford the corresponding tetrazolofuroazepine derivatives 2a-d via methylene shift. Under similar reaction conditions, the 2-iodomethyl-3,5,6,7-tetrahydrobenzofuranones 1e-h afford mixtures of the corresponding tetrazolofuroazepines 2e-h and the 4-azido-2-iodomethyl-2