Synthesis of the Fully Functionalized ABCDE Ring Moiety of Ciguatoxin

Kobayashi, Shōji; Heidary, Hossein; Sasaki, Shinya; Oguri, Hiroki; Hirama, Masahiro

doi:10.1021/ol0364475

Cited by 31 publications

(17 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…total synthesis of 1 and 2, 8,9a,b Lewis acid-mediated coupling of anomeric sulfone 46 with allyltrimethylsilane was attempted in the presence of AlCl 3 (Scheme 5). 14,28 However, ring-contraction products 51 and 52 were obtained in 50 and 20% yield, respectively, instead of the desired alkene 47. 29 This can be explained as shown in Scheme 5.…”

Section: Attempts To Construct the Tetrahydrooxocin E Ring Using A Chmentioning

confidence: 98%

“…All spectroscopic data are identical to those reported in the literature. 14 To a solution of the NAP-ether (1.14 g, 2.18 mmol) in MeOH (32 ml) and THF (16 ml) was added TsOH$H 2 O (57.0 mg, 0.218 mmol). The mixture was stirred for 27 h at room temperature and quenched with Et 3 N (1 ml).…”

Section: Hemiacetal 30mentioning

confidence: 99%

“…13 The intermediate 11 was expected to be a common precursor for the divergent synthesis of the left wings of 1, 2, 3 and 4. In our previous report, 14 the fully functionalized ABCDE ring moiety (10) of 4 was synthesized from 11 through installation of the dihydroxybutenyl substituent at C5 in the A ring and the tetrahydrooxepin E ring. In this publication, we have developed a stereocontrolled route to 5 from 11 using an asymmetric aldol condensation to regulate the C21-stereochemistry as a key transformation.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Stereocontrolled synthesis of the ABCDE ring moiety of ciguatoxin CTX3C

et al. 2004

Self Cite

View full text Add to dashboard Cite

Section: Attempts To Construct the Tetrahydrooxocin E Ring Using A Chmentioning

confidence: 98%

Section: Hemiacetal 30mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Stereocontrolled synthesis of the ABCDE ring moiety of ciguatoxin CTX3C

et al. 2004

Self Cite

View full text Add to dashboard Cite

“…Unfortunately, affinity for the IJKLM antibody of CTX-3C was relatively poor and the ABCDE antibody would not be expected to interact with the major pacific CTX (P-CTX-1). The recent synthesis of the ABCDE rings of P-CTX-1 (Kobayashi et al 2004) and total syntheses of CTX1B and 54-deoxy-CTX1B (Yamashita et al 2015) provide an opportunity to improve the targeting of the sandwich assay. Synthesis of fragments of C-CTX is needed before antibodies suitable for detecting the C-CTX can be developed (see Fig.…”

Section: Mitigationmentioning

confidence: 99%

Ciguatoxin and Ciguatera

Lewis

Vetter

2016

Marine and Freshwater Toxins

View full text Add to dashboard Cite

“…18). 55 Upon treatment of the resulting enol ether 65 with Pb(OAc) 4 and pyridine, oxidation proceeded at 5 C to produce the allylic acetate 66 in a stereo-and regio-controlled fashion. Nickel-catalyzed coupling of 66 with alkenylborate 58 yielded -adduct 67 (25%) and regioisomer 68 (45%).…”

mentioning

confidence: 99%

Bioorganic Studies Utilizing Rationally Designed Synthetic Molecules: Absolute Configuration of Ciguatoxin and Development of Immunoassay Systems

Oguri¹

2007

Bulletin of the Chemical Society of Japan

Self Cite

View full text Add to dashboard Cite

Ciguatoxins are the major causative toxins in ciguatera seafood poisoning. The limited availability of ciguatoxins has precluded structural elucidation and development of a reliable and specific immunoassay for detecting the toxins in contaminated fish. To seek a solution for the longstanding problem of ciguatera, we addressed the synthetic challenge by utilizing rationally designed model compounds of ciguatoxins. The C2 configuration and entire absolute configuration of ciguatoxin were successfully elucidated with minutest amounts of natural toxins, using an approach which combined partial structure synthesis, microscale chemical transformations, and the CD exciton chirality method. On the basis of the absolute configuration, the partial structures of ciguatoxins were designed and synthesized as haptens for the preparation of anti-ciguatoxin antibodies. Monoclonal antibodies (mAbs) against both ends of ciguatoxin CTX3C were prepared by immunization of mice with protein conjugates of synthetic haptens of the ABCDE-ring and the IJKLM-ring, in place of the natural toxin. Haptenic groups with surface areas larger than 400 Å 2 were required to produce mAbs, which could bind strongly to CTX3C itself. A direct sandwich enzyme-linked immunosorbent assay (ELISA) using these mAbs was shown to detect CTX3C at the ppb level with no cross-reactivity against other related marine toxins, including brevetoxin A, brevetoxin B, okadaic acid, or maitotoxin. In order to make the sandwich immunoassay protocol a general method for detecting other ciguatoxins congeners, the preparation of mAbs for the left-end of ciguatoxin was investigated. Expeditious synthesis of the left end of ciguatoxin with installation of the 3-butene-1,2-diol side-chain of the A-ring as well as surface plasmon resonance (SPR) analysis of the antibody-hapten interactions are also described.

show abstract

Synthesis of the Fully Functionalized ABCDE Ring Moiety of Ciguatoxin

Cited by 31 publications

References 35 publications

Stereocontrolled synthesis of the ABCDE ring moiety of ciguatoxin CTX3C

Stereocontrolled synthesis of the ABCDE ring moiety of ciguatoxin CTX3C

Ciguatoxin and Ciguatera

Bioorganic Studies Utilizing Rationally Designed Synthetic Molecules: Absolute Configuration of Ciguatoxin and Development of Immunoassay Systems

Contact Info

Product

Resources

About