title: Practical Total Syntheses of Acromelic Acids A and B.
abstract: Practical total syntheses of acromelic acids A (1) and B (2), which were scarce natural products isolated from toxic mushroom by Shirahama and Matsumoto, were accomplished in 13 (36% total yield) and 17 steps (6.9% total yield), respectively, from 2,6-dichloropyridine (8). Beginning with regioselective transformation of symmetric 8 by either ortho-lithiation or bromination, nitroalkenes 15 and 16 were provided. Stereoselective construction of the vicinal stereocenters at the C-3, 4 positions of 1 and 2 was performed by a Ni-catalyzed asymmetric conjugate addition of α-ketoesters to the nitroalkenes. Construction of the pyrrolidine ring was accomplished in a single operation via a sequence consisting of reduction of the nitro group, intramolecular condensation with the ketone, and reduction of the resulting ketimine.
authors.affiliation: School of Pharmaceutical Sciences, University of Shizuoka.
authors.forename: Makoto
authors.initials: M
authors.lastname: Inai
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ouchi
authors.forename: Aya
authors.initials: A
authors.lastname: Asahina
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Asakawa
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Hamashima
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kan
mesh_terms: D000363:Agaricales / Q000737:chemistry; D007608:Kainic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification; D015394:Molecular Structure
chemical_list: C051743:acromelic acid A; D007608:Kainic Acid; C438458:acromelic acid B