A Convenient Entry to 3-Methylidenechroman-2-ones and 2-Methylidenedihydrobenzochromen-3-ones
作者:Tomasz Janecki、Jakub Modranka、Anna Albrecht
DOI:10.1055/s-0030-1259046
日期:2010.12
A simple and versatile synthesis of 3-methylidenechroman-2-ones and 2-methylidenedihydrobenzochromen-3-ones has been developed. The reaction of phenols or naphthols with 3-methoxy-2-diethoxyphosphorylacrylate gave intermediate 3-diethoxyphosphorylchromen-2-ones or 2-diethoxyphosphorylbenzo-chromen-3-ones, respectively. These compounds were employed as Michael acceptors in the reaction with Grignard reagents to yield 4-substituted 3-diethoxyphosphorylchroman-2-ones or 1-substituted 2-diethoxyphosphoryldihydrobenzochromen-3-ones. The obtained adducts were next used as Horner-Wadsworth-Emmons reagents for the olefination of formaldehyde to give the final products.
A simple and effective synthesis of activated vinylphosphonates from 3-methoxy-2-diethoxyphosphorylacrylate
作者:Tomasz Janecki、Anna Albrecht、Jacek F. Koszuk、Jakub Modranka、Dominika Słowak
DOI:10.1016/j.tetlet.2010.02.108
日期:2010.4
A facile, efficient and general one-step procedure for the synthesis of 3-substituted 2-diethoxyphosphorylacrylates from 3-methoxy-2-diethoxyphosphorylacrylate 1b and nitrogen, carbon and phosphorus nucleophiles is presented. Reaction of 1b with 3,5-dimethoxyphenol in the presence of trifluoromethanesulfonic acid yields 3-diethoxyphosphoryl-5,7-dimethoxychromen-2-one. (C) 2010 Elsevier Ltd. All rights reserved.
Synthesis and biological evaluation of α-methylidene-δ-lactones with 3,4-dihydrocoumarin skeleton
and various substituents at position 4 were synthesized in a three step reaction sequence. Friedel–Crafts alkylation of phenols or naphthols using ethyl 3-methoxy-2-diethoxyphosphorylacrylate in the presence of trifluoromethanesulphonic acid gave 3-diethoxyphosphorylchromen-2-ones. These compounds were employed as Michael acceptors in the reaction with Grignardreagents to give adducts which were finally