A Versatile and General One-Pot Method for Synthesizing Bis-spiroketal Motifs
摘要:
A versatile and general method for the biomimetic construction of [5,5,5]- and [6,5,6]-bis-spiroketals, starting from easily accessible furan nuclei, by means of a powerful one-pot singlet oxygen-mediated cascade sequence is reported.
A new set of completely green methods utilising air, light, water and spirulina to transform readily accessible furan substrates into a diverse range of synthetically useful polyoxygenated motifs commonly found in natural products is presented herein.
The first transannular [4+3] cycloaddition reaction: synthesis of the ABCD ring structure of cortistatins
作者:Derek T. Craft、Benjamin W. Gung
DOI:10.1016/j.tetlet.2008.07.155
日期:2008.10
allene and a furan strategically located at across the ring from each other is synthesized using an allene ring closing metathesis reaction. Upon treatment of the macrocycle with a catalytic amount of Pd(OAc)(2) and other additives, the first transannular [4+3] cycloaddition occurred to yield 37% of a tetracyclic compound containing the ABC ring structure of the natural products cortistatins.