Syntheses of Linear Biosynthetic C 25 -Precursors of Leucosceptroids.

An efficient synthetic approach was developed and applied to the syntheses of four linear biosynthetic C 25 -precursors of leucosceptroids. The synthesis features a Julia-Kocienski olefination and a late-stage bioinspired photo-oxidation as key steps. The immunosuppressive effects of all synthetic compounds on mouse T cells and macrophage RAW264.7 were determined.