A lignin model oligomer with only β-O-4 linkages and a selectively deuterium-labelled methoxy group at the phenolic terminal units was synthesised to clarify the behaviour of the phenolic end of oligolignols. First, t-butoxycarbonylmethyl vanillin was synthesised and oligomerised by nucleophilic addition, a known method. The terminal of the oligomers was then subjected to nucleophilic addition to [3-OCD3]benzyl vanillin to achieve selective labelling of the terminal units. A deuterium-labelled lignin model oligomer (D-LM) was obtained through debenzylation and subsequent reduction. The results of thioacidolysis after methylation revealed that the degree of polymerisation was about five, and the deuterium-labelled phenylpropane unit was located only at the phenolic terminal moiety.

中文翻译：

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酚末端单元选择性氘标记甲氧基的 β-O-4 连接模型低聚木质醇的合成

仅含 β- 的木质素模型低聚物氧在酚末端单元上合成了-4键和选择性氘标记的甲氧基，以阐明低聚木质素酚末端的行为。第一的，t-丁氧基羰基甲基香草醛通过已知方法亲核加成合成并低聚。然后将寡聚物的末端亲核加成到[3-OCD3]苄基香草醛实现末端单元的选择性标记。通过脱苄基和随后的还原得到氘标记的木质素模型低聚物（D-LM）。甲基化后的硫代酸解结果表明，聚合度约为5，氘标记的苯丙烷单元仅位于酚末端部分。