Tellurium in organic synthesis: a general approach to buteno- and butanolides

The naturally occurring butanolides (−)-blastmycinolactol, (+)-blastmycinone, (−)-NFX-2, (+)-antimycinone as well as the four stereoisomers of the butenolide Acaterin were prepared in high enantiomeric purity using hydroxy-vinyl tellurides as starting materials.