Furanosteroid studies. Stereoselective synthesis of the A,B,E-ring core of wortmannin.
Alkyne oxazole 11c is converted in three steps, and approximately 45% overall yield, to furanolactone 21alpha having the A,B,E-ring core of the wortmannin (2) family of furanosteroids. The TiCl4-catalyzed insertion of EtO2C-CH=O between C3 and C10 in furanoacid 14d is >98% stereoselective via a pathway involving chemoselective lactonization of equilibrating aldol intermediates 23alpha,beta (dynamic kinetic resolution).
Sessions
E Hampton
EH
Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, USA.
O'Connor
Roger T
RT
Jacobi
Peter A
PA
D000447:Aldehydes; D000730:Androstadienes / Q000138:chemical synthesis*; D002384:Catalysis; D007783:Lactones / Q000737:chemistry; D015394:Molecular Structure; D010080:Oxazoles / Q000737:chemistry; D013237:Stereoisomerism; D013256:Steroids / Q000737:chemistry*; D000077191:Wortmannin
D000447:Aldehydes; D000730:Androstadienes; D007783:Lactones; D010080:Oxazoles; D013256:Steroids; C116609:3-hydroxybutanal; D000077191:Wortmannin