中文摘要：

四环杂萜类天然产物Liphagal含有新奇的[6-7-5-6]四环骨架,是磷酸肌醇3-激酶（PI3K）的有效抑制剂之一,可以选择性抑制细胞增殖和促进细胞死亡,在治疗炎症、免疫紊乱、癌症以及心血管疾病中有潜在的医用价值.从廉价的2,4,5-三甲氧基苯甲醛出发,通过Wittig反应、Cu催化的环化反应、选择性氢化、分子内Friedel-Crafts反应,以直线步骤最长7步,8.72%的总收率实现了8-epi-Liphagal高级中间体10的合成.

英文摘要：

The tetracyclic meroterpenoid natural product（＋）-liphagal is one of a number of natural inhibitors of phosphatidylinositol 3-kinase（PI3K）,which plays a central role in regulation of cell proliferation,cell survival,adhesion,membrane trafficking,glucose transport and neurite growth.Liphagal also shows inhibitory activity against PI3Kα with an IC50of 100 nmol L-1 making it as an agent for the treatment of inflammatory and autoimmune disorders as well as cancer and cardiovascular diseases.From a structural point of view,liphagal has an unprecedented [6-7-5-6] tetracyclic skeleton,and has attracted significant attention from the synthetic chemists.Starting from cheap and commercially available 2,4,5-trimethoxylbenzaldehyde and α-ionone,an advanced intermediate 10 for the synthesis of 8-epi-liphagal was achieved in the longest linear 7 steps and 8.72% yield.The key reactions include： Wittig reaction,Cu-catalyzed cyclization,chemoselective hydrogenation and Friedel-Crafts reaction.