First Total Synthesis of (β-5)-(β-O-4) Dihydroxytrimer and Dihydrotrimer of Coniferyl Alcohol (G): Advanced Lignin Model Compounds

Frontiers in Chemistry

Aurélien A. M. Peru¹  Florent Allais¹  Arnaud Haudrechy²  Amandine L. Flourat²  Jean-Hugues Renault² 

[1] URD Agro-Biotechnologies Industrielles (ABI), CEBB, AgroParisTech, Pomacle, France;Université de Reims Champagne Ardenne, CNRS, Institut de Chimie Moléculaire de Reims, UMR 7312, SFR Condorcet FR CNRS 3417, Reims, France;

关键词: lignin models;    coniferyl alcohol;    monolignol;    trimers;    total synthesis;    C-C coupling;   

DOI  :  10.3389/fchem.2019.00842

来源: DOAJ

【 摘 要 】

To investigate lignin degradation, scientists commonly use model compounds. Unfortunately, these models are most of the time simple β-O-4 dimers and do not sufficiently mimic the wide complexity of lignin structure (i.e., aliphatic side chains and robust C-C bonds). Herein, we present a methodology to access advanced lignin models through the first synthesis of two trimers of monolignol G—possessing side-chains and both robust β-5 bond and labile β-O-4 bond—via a chemo-enzymatic pathway. Key steps were (1) the C-C coupling via laccase-mediated oxidation, (2) the C-O coupling via a simple SN2 between a phenolate and a bromoketoester, and (3) a modified Upjohn dihydroxylation or a palladium-catalyzed hydrogenation. (β-5)-(β-O-4) dihydroxytrimer and dihydrotrimer of coniferyl alcohol (G) were obtained in good global yield, 9 and 20%, respectively, over nine steps starting from ferulic acid.

【 授权许可】

Unknown