Synthesis of the left hand unit of batzelladine F; Revision of the reported relative stereochemistry

Black, Gregory P.; Murphy, P. J.; Thornhill, Andrew J.; Walshe, Nigel; Zanetti, Cinzia

doi:10.1016/s0040-4020(99)00288-4

Cited by 45 publications

(25 citation statements)

References 20 publications

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“…Numerous batzelladines are known with different side chains;2a batzelladine K ( 53 ) which would be formed from the same precursor as the ptilocaulin natural products was isolated in 2007 39. Reaction of guanidine with bis enones, differing from 47 only in the alkyl side chains, followed by reduction affords batzelladines analogous to 53 in excellent yields 40. It is therefore not straightforward to develop the reaction of guanidine with bis enones as a laboratory route to the ptilocaulin family of natural products.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of 7-Epineoptilocaulin, Mirabilin B, and Isoptilocaulin. A Unified Biosynthetic Proposal for the Ptilocaulin and Batzelladine Alkaloids. Synthesis and Structure Revision of Netamines E and G

Pochapsky

Snider

2008

J. Org. Chem.

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Addition of guanidine to a 6-methylhexahydroindenone in MeOH at reflux afforded 7-epineoptilocaulin. A similar reaction with a 6-propylhexahydroindenone afforded netamine E. MnO 2 oxidation of 7-epineoptilocaulin and netamine E afforded mirabilin B and netamine G, respectively. The netamines have the side chains trans, not cis as was initially proposed. A unified biosynthetic scheme for the batzelladines and ptilocaulin family is proposed. Conjugate addition of guanidine to a bis enone followed by an intramolecular Michael reaction of the enolate to the other enone, aldol reaction, dehydration and enamine formation will lead to a tricyclic intermediate at the dehydroptilocaulin oxidation state. 1,4-Hydride addition will lead to ptilocaulin or 7-epineoptilocaulin depending on which face the hydride adds to. 1,2-Hydride addition will lead to isoptilocaulin. The key tricyclic intermediate was prepared from a tetrahydroindenone and guanidine and reduced with NaBH 4 to give a mixture rich in ptilocaulin and isoptilocaulin.

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Section: Resultsmentioning

confidence: 99%

Synthesis of 7-Epineoptilocaulin, Mirabilin B, and Isoptilocaulin. A Unified Biosynthetic Proposal for the Ptilocaulin and Batzelladine Alkaloids. Synthesis and Structure Revision of Netamines E and G

Pochapsky

Snider

2008

J. Org. Chem.

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“…Treatment of 6 with HCl (0.2 mol•L -1 ) gave the crude 5-hydroxypentanal, 6 which reacted with methyl magnesium iodide (CH 3 MgI) in Et 2 O afforded hexane-1,5-diol (7) 7 in 70% overall yield for two steps.…”

Section: Resultsmentioning

confidence: 99%

First Synthesis of a Series of New Natural Glucosides

Zhou

Cao

2006

Chin. J. Chem.

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Alkyl glucoside 1 and aryl glycosides 2-4 were highly stereospecifically synthesized over 4-6 steps from commercially available starting materials. The coupling reaction of the acetobromo-α-D-glucose with the unprotective dihydroxy aglycon in the presence of silver oxide, or with aromatic aglycon in the presence of sodium hydroxide produced the key intermediate. Only β-configuration glycosides were formed in this procedure. The synthesis of all these glycosides was reported for the first time.

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“…The Murphy group also independently found that the originally proposed relative stereochemistry of the tricyclic core of batzelladine F ( 301f ) was incorrect. 400-403 They completed the biomimetic synthesis of crambescidin 359 ( 4b ) in 2003. 404,405 The synthesis of 4b started with the Wittig reaction of 326 and 333 (Fig.…”

Section: The Crambescidin/batzelladine Alkaloidsmentioning

confidence: 99%

Syntheses of cyclic guanidine-containing natural products

Chen

2015

Tetrahedron

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Naturally occurring guanidine derivatives frequently display medicinally useful properties. Among them, the higher order pyrrole-imidazole alkaloids, the dragmacidins, the crambescidins/batzelladines, and the saxitoxins/tetradotoxins have stimulated the development of many new synthetic methods over the past decades. We provide here an overview of the syntheses of these cyclic guanidine-containing natural products.

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Synthesis of the left hand unit of batzelladine F; Revision of the reported relative stereochemistry

Cited by 45 publications

References 20 publications

Synthesis of 7-Epineoptilocaulin, Mirabilin B, and Isoptilocaulin. A Unified Biosynthetic Proposal for the Ptilocaulin and Batzelladine Alkaloids. Synthesis and Structure Revision of Netamines E and G

Synthesis of 7-Epineoptilocaulin, Mirabilin B, and Isoptilocaulin. A Unified Biosynthetic Proposal for the Ptilocaulin and Batzelladine Alkaloids. Synthesis and Structure Revision of Netamines E and G

First Synthesis of a Series of New Natural Glucosides

Syntheses of cyclic guanidine-containing natural products

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