A new type of chiral sulfur ylides has been synthesized and their reactivities against carbonyl compounds tested, showing a high degree of stereoselectivity in the formation of transepoxyamides under very mild reaction conditions.
A new type of chiral sulfoniumsalts that are characterized by a bicyclic system has been designed and synthesized from α‐amino acids. Their corresponding ylides, which were prepared by basic treatment of the sulfoniumsalts, reacted smoothly with a broad array of simple and chiral aldehydes to provide trans‐epoxy amides in reasonable to very good yields and excellent stereoselectivities (>98 %). The
Total synthesis of (−)-exiguolide, the natural enantiomer, has been accomplished for the first time. The bis(tetrahydropyran) subunit was efficiently synthesized via consecutive olefin cross-metathesis/intramolecular oxa-conjugate addition/reductiveetherification. Construction of the 20-membered macrocycle was achieved by Yamaguchi macrolactonization. Stereoselective introduction of the (E,Z,E)-triene