Total Synthesis of (±)-Calcaridine A and (±)-epi-Calcaridine A
摘要:
The first total synthesis of the Leucetta alkaloid calcaridine A is described based on a biosynthetic postulate. Application of an oxidative rearrangement of a 4,5-disubstituted imidazole leads to the formation of both calcaridine A and epi-calcaridine A. An X-ray crystal structure determination on the latter has allowed the assignment of the relative configuration of the epimeric natural product and calcaridine A by extrapolation.
A biomimetically guided total synthesis of the Leucetta-derived aminoimidazole alkaloid, calcaridine A, is described. The synthesis relies on position selective metalations of a 4,5-diiodoimidazole derivative to provide a tetrasubstituted imidazole. Subjection of this polysubstituted imidazole derivative to oxidative rearrangement with a Davis oxaziridine provides the corresponding imidazolone core of calcaridine A.
Total Synthesis of (±)-Calcaridine A and (±)-<i>epi</i>-Calcaridine A
作者:Panduka B. Koswatta、Rasapalli Sivappa、H. V. Rasika Dias、Carl J. Lovely
DOI:10.1021/ol802018r
日期:2008.11.6
The first total synthesis of the Leucetta alkaloid calcaridine A is described based on a biosynthetic postulate. Application of an oxidative rearrangement of a 4,5-disubstituted imidazole leads to the formation of both calcaridine A and epi-calcaridine A. An X-ray crystal structure determination on the latter has allowed the assignment of the relative configuration of the epimeric natural product and calcaridine A by extrapolation.