Domino ‘Michael-retro-Michael-aldol’ reactions of 1,3-bis-silyl enol ethers with 3-formylchromones
作者:Peter Langer、Bettina Appel
DOI:10.1016/j.tetlet.2003.09.008
日期:2003.10.20
Functionalized benzophenones were prepared by domino 'Michael-retro-Michael-aldol' reactions of 1,3-bis-silyl enol ethers with 3-formylchromones. (C) 2003 Elsevier Ltd. All rights reserved.
Domino Michael/Retro-Michael/Mukaiyama-Aldol Reactions of 1,3-Bis-Silyl Enol Ethers with 3-Acyl- and 3-Formylbenzopyrylium Triflates – Synthesis of Functionalised 2,4′-Dihydroxybenzophenones
3-bis-silyl enol ethers with 3-acyl- and 3-formylbenzopyrylium triflates, which can be generated in situ from 3-acyl- and 3-formylchromones, affords a great variety of functionalised 2,4′-dihydroxybenzophenones and 4-(2-hydroxybenzoyl)salicylates. These products are formed by a domino Michael/retro-Michael/Mukaiyama-aldol reaction. This methodology is successfully applied to the synthesis of novel UV-A/B and