Studies towards the total synthesis of lycoposerramine A. Synthesis of a model for the tetracyclic core.
Lycoposerramine A (1) is a pentacyclic alkaloid isolated in 2001 by Takayama and co-workers. A concise synthesis of a model compound 8 for the tetracyclic core of this natural product is described. Key steps include the desymmetrising free-radical cyclisation of compound 7 to give compound 18 and spirocyclisation of compound 26 to give compound 8. Earlier approaches using a novel high-yielding stereoselective anionic cyclisation of a cyclohexa-1,4-diene are also reported.
Elliott
Mark C
MC
School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, UK. elliottmc@cardiff.ac.uk
Paine
James S
JS
D000470:Alkaloids / Q000138:chemical synthesis*; D001688:Biological Products / Q000138:chemical synthesis; D003500:Cyclization; D005609:Free Radicals / Q000737:chemistry; D008958:Models, Molecular; D010069:Oxadiazoles / Q000138:chemical synthesis*; D013141:Spiro Compounds / Q000737:chemistry
D000470:Alkaloids; D001688:Biological Products; D005609:Free Radicals; D010069:Oxadiazoles; D013141:Spiro Compounds; C445719:lycoposerramine-A