Synthesis of the 1,3-Dioxolane Ring System of the Trichothecenes Sambucinol and Sporol via a Stereoselective Claisen Rearrangement

Abstract

The major stereoisomer from the Claisen rearrangement of allyl vinyl ether 10 was shown to be keto nitrile 12 by an X-ray crystallographic analysis on the derived hydroxy nitrile 15. In a similar fashion, allyl vinyl ether 22 produced keto nitrile 23a. This substance was converted into hydroxymethyl ketal 25, which bears the 1,3-dioxolane ring system present in sambucinol 1 and sporol 2. © 1987, American Chemical Society. All rights reserved.