The structure of ryanodine

Wiesner, K.

doi:10.1135/cccc19682656

Cited by 22 publications

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“…1 shows the schematic formula as established by this X-ray investigation and the relationship between ryanodine, ryanodol and ryanodol p-bromobenzyl ether. The extensive degradation studies led first to the elucidation of the structure and the determination of the absolute configuration of anhydroryanodine, the dehydration product of ryanodine (Babin, Forrest, Valenta & Wiesner, 1962;Wiesner, 1963) and later to the proposals for the structures of ryanodol and ryanodine (Wiesner, Valenta & Findlay, 1967;Wiesner, 1968). This paper reports the crystal structure determination of ryanodolp-bromobenzyl ether, C27H3708Br, and confirms the molecular structures for this and related compounds proposed by Wiesner et al, except for their assignment of configuration at the carbon atom carrying the isopropyl group.…”

Section: Introductionmentioning

confidence: 99%

The crystal structure of ryanodol p-brombenzyl ether

Srivastava¹,

Przybylska²

1970

Acta Crystallogr Sect B

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The crystals of ryanodol-p-bromobenzyl ether, C27H37OsBr, belong to the space group P212121 and the unit-cell dimensions are: a=17.65+0.03, b=14.43+0"02 and c=10.11 +0.02/L The structure was solved by the heavy-atom method from three-dimensional X-ray intensity data collected photographically. The atomic parameters were refined by block-diagonal least squares to the R value of 0.090. The results confirm the structure and relative stereochemistry independently deduced by chemical means by K. Wiesner, except for the configuration at one of the eleven asymmetric centres. Only one hydrogen bond (intermolecular) was found. All other hydrogen atoms of OH groups make intra-and intermolecular contacts with oxygen atoms which do not deviate from the sum of the van der Waals radii.

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Section: Introductionmentioning

confidence: 99%

The crystal structure of ryanodol p-brombenzyl ether

Srivastava¹,

Przybylska²

1970

Acta Crystallogr Sect B

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“… 10 Although a molecular formula was provided in the initial report, two decades of chemical degradation and derivatization studies were required before the structure was correctly assigned. 11 − 13 Since the isolation of 1 , several structurally related natural products that share a common carbocyclic core but vary in peripheral oxidation, such as (+)-spiganthine ( 2 ) and (+)-20-deoxyspiganthine ( 3 ), 14 , 15 have also been identified as modulators of RyR function.…”

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confidence: 99%

Chemical Synthesis of (+)-Ryanodine and (+)-20-Deoxyspiganthine

Han

Virgil

et al. 2017

ACS Cent. Sci.

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(+)-Ryanodine is a natural product modulator of ryanodine receptors, important intracellular calcium ion channels that play a critical role in signal transduction leading to muscle movement and synaptic transmission. Chemical derivatization of (+)-ryanodine has demonstrated that certain peripheral structural modifications can alter its pharmacology, and that the pyrrole-2-carboxylate ester is critical for high affinity binding to ryanodine receptors. However, the structural variation of available ryanodine analogues has been limited by the challenge of site-specific functionalization of semisynthetic intermediates, such as (+)-ryanodol. Here we report a synthetic strategy that provides access to (+)-ryanodine and the related natural product (+)-20-deoxyspiganthine in 18 and 19 steps, respectively. A key feature of this strategy is the reductive cyclization of an epoxide intermediate that possesses the critical pyrrole-2-carboxylate ester. This approach allows for the direct introduction of this ester in the final stage of the synthesis and provides a framework for the synthesis of previously inaccessible synthetic ryanoids.

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“…The three ryanodane structures 3 – 5 would be constructed from 8 by systematic manipulations at the C2‐ and C3‐positions. Acid treatment of 5 would promote dehydrative C−C bond cleavage to generate 6 . The C15‐lactone reorganization from 6 was planned to build 7 , but was not performed, as the structure of cinnacasol turned out to be that of 6 , and not 7 (see below).…”

Section: Methodsmentioning

confidence: 99%

“…The protonated intermediate 18A , which originated from 18 , underwent dehydrative Grob‐type fragmentation into 19 by scission of the C2−O and C1−C15 bonds (Figure ) . Intriguingly, application of the same acidic conditions to 14 provided 15 while retaining the ring system.…”

Section: Methodsmentioning

confidence: 99%

Unified Total Synthesis of 3‐epi‐Ryanodol, Cinnzeylanol, Cinncassiols A and B, and Structural Revision of Natural Ryanodol and Cinnacasol

2016

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Ryanodane diterpenoids structurally share an extremely complex fused ring system, but differ in the substitution patterns of the hydroxy groups. Since these congeners exhibit various biologically important functions, their efficient chemical constructions have been greatly anticipated. We previously accomplished the total synthesis of ryanodine (1) using pentacycle 8 as the advanced intermediate. Here, we report the unified total syntheses of four distinct diterpenoids, 3-epi-ryanodol (3), cinnzeylanol (4), cinncassiols B (5), and A (6), from 8, all within 10 steps. A series of highly optimized chemo- and stereoselective reactions and protecting-group manipulations enabled assembly of the densely oxygenated structures of 3-6. Furthermore, the present synthetic studies established the C13S stereochemisty of 5-7 and revised the proposed structures of natural ryanodol (2) and cinnacasol (7) to be those of 3 and 6, respectively.

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The structure of ryanodine

Cited by 22 publications

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The crystal structure of ryanodol p-brombenzyl ether

The crystal structure of ryanodol p-brombenzyl ether

Chemical Synthesis of (+)-Ryanodine and (+)-20-Deoxyspiganthine

Unified Total Synthesis of 3‐epi‐Ryanodol, Cinnzeylanol, Cinncassiols A and B, and Structural Revision of Natural Ryanodol and Cinnacasol

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