The first total synthesis of the natural cytotoxic agent sporiolide A has been accomplished from D-glucal in 16 steps with 6.1% overall yield. Carbohydrates were applied as the chiral templates to manipulate the absolute configuration during the synthesis. Pyridinium chlorochromate (PCC)-promoted transformation of the cyclic enol-ether to lactone, followed by Yamaguchi esterification and intramolecular ring closure metathesis, greatly facilitates synthesis of the target compound.
Stereoselective total synthesis of (+)-boronolide, (+)-anamarine, 8-epi-spicegerolide
A stereoselective total synthesis of the naturally occurring cytotoxic lactones (+)-boronolide, (+)-anamarine, and 8-epi-spicigerolide is described. D-Xylose has been used as a chiral source to construct the four contiguous oxygenated stereogenic centers of target molecules. The diastereoselective allylation was performed using Brown's protocol and the lactone moiety was prepared by ring closing metathesis. (C) 2013 Elsevier Ltd. All rights reserved.