Department of Chemistry and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu, Taiwan 30013, ROC.
Org Biomol Chem. 2012 Jul 28;10(28):5456-65. doi: 10.1039/c2ob25575h. Epub 2012 Jun 6.
An efficient and convergent route for the synthesis of the natural product (+)-lithospermic acid, which possesses anti-HIV activity, was accomplished. The (±)-trans-dihydrobenzo[b]furan core therein was prepared by two different strategies. The first strategy involved the use of a palladium-catalyzed annulation to generate an appropriately substituted benzo[b]furan ester followed by a stereoselective reduction of a carbon-carbon double bond with Mg-HgCl(2)-MeOH. The second strategy relied on an aldol condensation between a suitably substituted methyl arylacetate and 3,4-dimethoxybenzaldehyde, followed by cyclization. Finally, a total synthesis of (+)-lithospermic acid was completed via coupling of a trans-dihydrobenzo[b]furan cinnamic acid with an enantiomerically pure methyl lactate.
完成了具有抗 HIV 活性的天然产物（+）-马钱子酸的高效、收敛合成路线。其中的（±）-反式二氢苯并[b]呋喃核通过两种不同的策略制备。第一种策略涉及使用钯催化的环化反应生成适当取代的苯并[b]呋喃酯，然后用 Mg-HgCl(2)-MeOH 选择性还原碳-碳双键。第二种策略依赖于适当取代的甲基芳基乙酸酯和 3,4-二甲氧基苯甲醛之间的醛缩合，然后环化。最后，通过反式二氢苯并[b]呋喃肉桂酸与对映体纯的乳酸甲酯的偶联完成了（+）-马钱子酸的全合成。
