Total Synthesis of (+)-Blastmycinone, (−)-Litsenolide C<sub>1</sub>, and Related Natural Trisubstituted Lactones via Alkynyltungsten Compounds
作者:Ming-Jung Chen、Ching-Yu Lo、Chih-Chien Chin、Rai-Shung Liu
DOI:10.1021/jo0002487
日期:2000.10.1
A general method for total synthesis of natural trisubstituted gamma-lactones is developed on the basis of the chemistry of alkynyltungsten compounds. The key step in this approach involves the cycloalkenation of tungsten-eta1-(3R,4S)-pent-1-yne-3,4-diol with aldehydes to give tungsten-oxacarbenium salts, further leading to 3-alkylidene-4-hydroxy-5-methyl-gamma-lactones upon demetalation. This synthetic
根据炔烃钨化合物的化学性质,开发了一种全合成天然三取代γ-内酯的通用方法。该方法的关键步骤涉及将钨-eta1-(3R,4S)-戊-1-炔-3,4-二醇与醛进行环烯化反应生成钨-氧杂碳鎓盐,进一步导致3-亚烷基-4-羟基脱金属时的-5-甲基-γ-内酯。对于炔醛和钨-eta1-(3R,4S)-戊-1-炔-3,4-二醇的MOM衍生物,该合成序列进展顺利。将所得丁内酯产物转化为天然三取代丁内酯,包括(+)-blastmycinone,(+)-blastmycinactactol,(+)-antimycinone,NFX-2和(+)-isodihydromahubanolideA。通过基于(R )-乳酸乙酯,可以通过几个步骤制备天然(-)-litsenolide C1。