title: Enantioselective total syntheses of FR901464 and spliceostatin A and evaluation of splicing activity of key derivatives.
abstract: FR901464 (1) and spliceostatin A (2) are potent inhibitors of spliceosomes. These compounds have shown remarkable anticancer activity against multiple human cancer cell lines. Herein, we describe efficient, enantioselective syntheses of FR901464, spliceostatin A, six corresponding diastereomers and an evaluation of their splicing activity. Syntheses of spliceostatin A and FR901464 were carried out in the longest linear sequence of 9 and 10 steps, respectively. To construct the highly functionalized tetrahydropyran A-ring, we utilized CBS reduction, Achmatowicz rearrangement, Michael addition, and reductive amination as key steps. The remarkable diastereoselectivity of the Michael addition was specifically demonstrated with different substrates under various reaction conditions. The side chain B was prepared from an optically active alcohol, followed by acetylation and hydrogenation over Lindlar's catalyst. The other densely functionalized tetrahydropyran C-ring was derived from readily available (R)-isopropylidene glyceraldehyde through a route featuring 1,2-addition, cyclic ketalization, and regioselective epoxidation. These fragments were coupled together at a late stage through amidation and cross-metathesis in a convergent manner. Six key diastereomers were then synthesized to probe the importance of specific stereochemical features of FR901464 and spliceostatin A, with respect to their in vitro splicing activity.
authors.affiliation: Department of Chemistry and Department of Medicinal Chemistry, Purdue University , 560 Oval Drive, West Lafayette, Indiana 4790, United States.
authors.forename: Arun K
authors.initials: AK
authors.lastname: Ghosh
authors.forename: Zhi-Hua
authors.initials: ZH
authors.lastname: Chen
authors.forename: Kerstin A
authors.initials: KA
authors.lastname: Effenberger
authors.forename: Melissa S
authors.initials: MS
authors.lastname: Jurica
mesh_terms: D000475:Alkenes / Q000737:chemistry; D002384:Catalysis; D045744:Cell Line, Tumor; D006801:Humans; D015394:Molecular Structure; D011714:Pyrans / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology*; D012326:RNA Splicing; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology*; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; C104486:FR 901464; D011714:Pyrans; D013141:Spiro Compounds; C553684:spliceostatin A; C013658:propylene