Synthesis of (-)-stemoamide using a stereoselective anti-aldol step.
The synthesis of (-)-stemoamide was achieved in 11 steps from 5-acetoxy-N-crotyl pyrrolidinone. A chiral N-acyl thiazolidinethione was employed in a stereoselective addition to a cyclic N-acyl iminium ion to install the required stereochemistry of carbon C9a. This iminium ion addition product was employed in a stereoselective MgBr2-catalyzed anti-aldol reaction to install the required stereochemistry of carbons C8 and C9. The X-ray crystal analysis of (-)-stemoamide confirmed the structure and the stereochemical outcome of these selective reactions.
Olivo
Horacio F
HF
Division of Medicinal and Natural Products Chemistry, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, USA. horacio-olivo@uiowa.edu
Tovar-Miranda
Ricardo
R
Barragán
Efraín
E
D000447:Aldehydes / Q000737:chemistry*; D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D001381:Azepines / Q000737:chemistry; D018360:Crystallography, X-Ray; D006575:Heterocyclic Compounds, 3-Ring / Q000138:chemical synthesis* / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism; D053778:Thiazolidines / Q000737:chemistry
D000447:Aldehydes; D000470:Alkaloids; D001381:Azepines; D006575:Heterocyclic Compounds, 3-Ring; D007783:Lactones; D053778:Thiazolidines; C519217:stemoamide; C033089:thiazoline-2-thione; C116609:3-hydroxybutanal