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Journal articles
A simple two steps ytterbium triflate‐catalysed preparation of 2,2‐dimethyl‐2h‐chromenes from salicylaldehydes and 2‐methylpropene
Abstract : The preparation of various 2,2‐dimethyl‐2H‐chromenes was achieved in two steps via an ytterbium triflate‐catalysed reaction between salicylaldehydes, trimethylorthoformate and 2‐methylpropene. From salicylaldehyde, two reaction products were characterised: 4‐methoxy‐2,2‐dimethylchroman and 2‐(1,3‐dimethoxy‐3‐methylbutyl)phenol. The former compound probably results from a Lewis acid‐catalysed [2+4] cycloaddition between the intermediate quinonemethide and 2‐methylpropene whereas the latter may occur via a reaction related to a carbonyl‐ene reaction between the quinonemethide and 2‐methylpropene. Both compounds were subjected to a catalytic acidic treatment leading to 2,2‐dimethyl‐2H‐chromene. Starting from various salicylaldehydes, the scope of this method was investigated.
https://hal-pasteur.archives-ouvertes.fr/pasteur-00167163
Contributor : Yves Janin Connect in order to contact the contributor
Submitted on : Thursday, August 16, 2007 - 11:47:03 AM
Last modification on : Tuesday, October 19, 2021 - 10:26:38 PM
Contributor : Yves Janin Connect in order to contact the contributor
Submitted on : Thursday, August 16, 2007 - 11:47:03 AM
Last modification on : Tuesday, October 19, 2021 - 10:26:38 PM
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