Total synthesis and absolute stereochemical assignment of (+)- and (-)-galbulimima alkaloid 13.
We describe the total synthesis of (+)- and (-)-galbulimima alkaloid 13. The absolute stereochemistry of natural (-)-galbulimima alkaloid 13 is revised to 2S. Sequential use of catalytic cross-coupling and cross-metathesis reactions followed by an intramolecular Diels-Alder reaction provided the required trans-decalin AB-ring system and masked the C16 carbonyl as an N-vinyl carbamate for late-stage unveiling in the form of the necessary C16 enone. A vinyl radical cyclization secured the C-ring, while successful execution of our strategy for introduction of the CDE-ring system in complex galbulimima alkaloids provided the target pentacycle with complete diastereoselection.
Movassaghi
Mohammad
M
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. movassag@mit.edu
Hunt
Diana K
DK
Tjandra
Meiliana
M
D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry* / Q000145:classification; D015394:Molecular Structure; D013237:Stereoisomerism
C518378:Galbulimima alkaloid 13; D006571:Heterocyclic Compounds