Ozonolysis of Morita–Baylis–Hillman adducts originated from aromatic aldehydes: an expeditious diastereoselective approach for the preparation of α,β-dihydroxy-esters
作者:Carlos A.M. Abella、Patrícia Rezende、Michele F. Lino de Souza、Fernando Coelho
DOI:10.1016/j.tetlet.2007.10.149
日期:2008.1
We disclose herein ozonolysis of Morita-Baylis-Hillman adducts originated from aromatic aldehydes. This efficient reaction provides alpha-ketoesters with different substitution patterns on the aromatic ring. Diastercoselective reduction of the corresponding alpha-ketoester obtained in the oxidative cleavage step provides alpha,beta-dihydroxy-esters with excellent degree of anti diastereoselection. The method is simple and easy to execute and is therefore a valuable alternative to prepare either alpha-ketoesters or alpha-dihydroxy-esters. (c) 2007 Elsevier Ltd. All rights reserved.
AN ALTERNATIVE ROUTE TO THE SYNTHESIS OF LIGNANS INTERMEDIATES
作者:Andrea Masunari、Elisa Ishida、Giordano Trazzi、Wanda P. Almeida、Fernando Coelho
DOI:10.1081/scc-100104463
日期:2001.1.1
The preparation of beta -hydroxylignans intermediates via Baylis-Hillman reaction is described.
Diastereoselective synthesis of β-piperonyl-γ-butyrolactones from morita-baylis-hillman adducts. highly efficient synthesis of (±)-yatein, (±)-podorhizol and (±)-epi-podorhizol
Starting from a Morita-Baylis-Hillman adduct we describe a simple and very efficient method for the diastereoselective preparation of hydroxylated beta-piperonyl-gamma-butyrolactones. To exemplify the efficiency of this approach we also describe a highly efficient synthesis for the biologically active lignans (+/-)-yatein, (+/-)-podorhizol and (+/-)-epi-podorhizol.