Stereoselective Synthesis of the Lituarine Tricyclic Spiroacetal
摘要:
Oxidative cyclizations of 2-(4-hydroxybutyl)furan derivatives provide spirobutenolide acetals directly; on the basis of this methodology, we describe an asymmetric synthesis of a tricyclic spirobutenolide precursor to the C(7-18) fragment common to lituarines A-C.
Stereoselective Synthesis of the Lituarine Tricyclic Spiroacetal
摘要:
Oxidative cyclizations of 2-(4-hydroxybutyl)furan derivatives provide spirobutenolide acetals directly; on the basis of this methodology, we describe an asymmetric synthesis of a tricyclic spirobutenolide precursor to the C(7-18) fragment common to lituarines A-C.
Rendering Schrock-type Molybdenum Alkylidene Complexes Air Stable: User-Friendly Precatalysts for Alkene Metathesis
作者:Johannes Heppekausen、Alois Fürstner
DOI:10.1002/anie.201102012
日期:2011.8.16
A matter of convenience: Schrock molybdenumalkylidenes are amongst the most powerful olefin metathesis catalysts known to date, but their sensitivity to air and moisture mandates their handling in a glove‐box or by Schlenk techniques. This inconvenience is circumvented by using the corresponding phenanthroline‐ or bipyridine adducts, which are bench‐stable and hence very user‐friendly. The active