A stereoselective total synthesis of 13-membered macrocycle PF1163A, an antifungal agent, has been accomplished for the first time starting from D-xylose. This approach involves a diastereoselective allylation of lactal ether,(3a) reductive ring opening of tetrahydrofuran ring,(3b) asymmetric methylation reaction, Yamaguchi esterification, and ring closing metathesis as key steps. (C) 2014 Elsevier Ltd. All rights reserved.
A stereoselective total synthesis of 13-membered macrocycle PF1163A, an antifungal agent, has been accomplished for the first time starting from D-xylose. This approach involves a diastereoselective allylation of lactal ether,(3a) reductive ring opening of tetrahydrofuran ring,(3b) asymmetric methylation reaction, Yamaguchi esterification, and ring closing metathesis as key steps. (C) 2014 Elsevier Ltd. All rights reserved.
Lactols and their ethers undergo smooth allylation with allyltrimethylsilane in the presence of 5 mol % iodine in dichloromethane at −78 °C to afford C-allylfuranosides in good yields and with high diastereoselectivity. The use of iodine makes this method simple, convenient and practical. This is the first report on the allylation of lactols with allyltrimethylsilane using molecular iodine as a catalyst