Stereoselective Syntheses of Cyclic Microsclerodermin Derivatives

Starting from l-xylose and d-arabinose, six different cyclic microscleroderma derivatives were successfully obtained. Key steps of the syntheses are, on the one hand, Sakurai allylations, whose stereochemical course depends on the Lewis acid used, and on the other hand, photochemical Wolff rearrangements in the presence of complex aminofuranosides. Finally, aromatic side chains were introduced via cross metathesis.