This work was financially supported by the National Natural Science Foundation of China (Nos. 21272129 and 21372133) and "111" Project of Ministry of Educa- tion of China (No. B06005). We also thank Prof. Er-Cai Shang and Dr. Yan-Jun Guo for their kind advices.
The structure of osthole has been modified to improve its larvicidal activity against mosquitoes. A new efficient synthesis of osthole derivatives with Grignard reagents has been developed, which employs CuI and LiCI ...