Preparation of E-α-stannyl-β-trimethylsilylethynylacrylate, building block for polyconjugated ylidenebutenolide and its derivatives, by novel E-selective ethynylstannylation of propiolate
摘要:
E-alpha-Stannyl-beta-trimethylsilylethynylacrylates, which are effective building blocks for the polyconjugated ylidenebutenolides and its modified derivatives, were directly synthesized via novel E-selective ethynylstannylation of propiolic acid esters. These building blocks were applied to the syntheses of the ylidenebutenolide segment in the previous peridinin synthesis and a short chain Z-eneyne ester derivative, by the sequential Stille and Sonogashira couplings with the corresponding epoxide and vinyl iodide segments. (C) 2015 Elsevier Ltd. All rights reserved.
Total Synthesis of Enantiopure Pyrrhoxanthin: Alternative Methods for the Stereoselective Preparation of 4-Alkylidenebutenolides
作者:Belén Vaz、Leticia Otero、Rosana Álvarez、Ángel R. de Lera
DOI:10.1002/chem.201301873
日期:2013.9.23
A new stereocontrolled total synthesis of the configurationally labile C37‐norcarotenoid pyrrhoxanthin in enantiopure form has been completed. A highlystereoselective Horner–Wadsworth–Emmons (HWE) condensation of a C17‐allylphosphonate and a C20‐aldehyde was used as the last conjunctive step. Both a Sonogashira reaction to form the C17‐phosphonate and the final HWE condensation proved to be compatible