Enantioselective Total Synthesis of the Guaianolide (−)-Dehydrocostus Lactone by Enediyne Metathesis
作者:Felix Kaden、Peter Metz
DOI:10.1021/acs.orglett.1c00008
日期:2021.2.19
The hydroazulene core of the bioactive sesquiterpenoid (−)-dehydrocostus lactone was generated by domino enediyne metathesis. A triple hydroboration/oxidation of the resultant conjugated triene installed three out of four stereogenic centers of the target in a single step. The enantiopure acyclic metathesis substrate was readily available by an asymmetric anti aldol reaction. Masking of the γ-lactone
Domino metathesis of the acyclic substrates 2 and 3 prepared by asymmetric anti aldol reactions gave access to suitably functionalized carbobicyclic cores of (−)-dehydrocostus lactone (1). Subsequent transformation of these hydroazulenes to triol 4 by multiple hydroboration/oxidation installed three out of four stereogenic centers of the target sesquiterpenoid 1 in a single step and paved the way for