Synthese eines tetracyclischen Lactams durch regioselektive Haller-Bauer-Spaltung/Grob Fragmentierung
摘要:
Synthesis of a Tetracyclic Lactam by Regioselective Haller-Bauer Scission/Grob Fragmentation The polycyclic ketone 3b, which has been synthesized in good yield as a model compound in search of a new approach to taxane derivatives, undergoes a regiospecific Haller-Bauer fragmentation leading eventually to lactam 4.
The methylketal 9 b, obtained in five steps from 2,6-dimethylbenzoquinone, is transformed by photolysis into the highly functionalized taxane precursor 11 d.