title: Total syntheses of [17]- and [18]dehydrodesoxyepothilones B via a concise ring-closing metathesis-based strategy: correlation of ring size with biological activity in the epothilone series.
abstract: A convergent ring-closing metathesis strategy has been employed for the highly concise syntheses of 10,11-dehydro-13,14-[17]desoxyepothilone B ([17]ddEpoB) and 10,11-dehydro-14,15-[18]desoxyepothilone B ([18]ddEpoB), which are 17- and 18-membered ring homologues of 10,11-dehydro-12,13-desoxyepothilone B ([16]ddEpoB or epothilone 490). We have demonstrated that the ring-closing metathesis (RCM) provides [17]ddEpoB or [18]ddEpoB with a high level of stereocontrol in the generation of the desired olefin in the products. These analogues were evaluated for antitumor activity. The results from the in vitro assays revealed that the [17]ddEpoB analogue is highly active against various tumor cell lines with a potency comparable to that of [16]ddEpoB. This is the first example of a 17-membered ring macrolactone epothilone that has retained its antitumor activity. In contrast, the biological data revealed that [18]ddEpoB is significantly less active than either [17]ddEpoB or the parent [16]ddEpoB.
authors.affiliation: Laboratory for Bioorganic Chemistry, Preclinical Pharmacology Core Facility and Analytical Pharmacology Core Facility, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10021, USA.
authors.forename: Alexey
authors.initials: A
authors.lastname: Rivkin
authors.forename: Jon T
authors.initials: JT
authors.lastname: Njardarson
authors.forename: Kaustav
authors.initials: K
authors.lastname: Biswas
authors.forename: Ting-Chao
authors.initials: TC
authors.lastname: Chou
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Danishefsky
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D034261:Epothilones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D009362:Neoplasm Metastasis / Q000188:drug therapy; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D034261:Epothilones; C114026:desoxyepothilone B