title: Concise total syntheses of (±)-mesembrane and (±)-crinane.
abstract: A straightforward and unified strategy to access Amaryllidaceae alkaloids comprising a cis-3a-aryloctahydroindole scaffold has been developed. The strategy features Eschenmoser-Claisen rearrangement of allylalcohol as a key step for the installation of all-carbon quaternary stereocenters present in these alkaloids. The consequent iodolactonization-reduction-oxidation sequence beautifully assembles the advanced intermediate keto-aldehyde 10a, b in synthetically viable yields. The methodology has been successfully applied in the efficient syntheses of (±)-mesembrane (1a) and (±)-crinane (2a).
authors.affiliation: Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, MP-462066, India. alakesh@iiserb.ac.in.
authors.forename: Mrinal Kanti
authors.initials: MK
authors.lastname: Das
authors.forename: Subhadip
authors.initials: S
authors.lastname: De
authors.lastname: Shubhashish
authors.forename: Alakesh
authors.initials: A
authors.lastname: Bisai
mesh_terms: D000447:Aldehydes / Q000138:chemical synthesis / Q000737:chemistry; D047151:Amaryllidaceae Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D000586:Amination
chemical_list: D000447:Aldehydes; D047151:Amaryllidaceae Alkaloids; C504763:crinane; C000603236:mesembrane