Synthesis and structural characterization of the isomuscarines

Kempter, Irina; Frensch, Britta; Kopf, Thomas; Kluge, Ralph; Csuk, René; Svoboda, Ingrid; Fueß, H.; Hartung, Jens

doi:10.1016/j.tet.2013.12.085

Cited by 5 publications

(6 citation statements)

References 45 publications

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“…Then, compound 7 was treated with excess of iodomethane and 1,2,2,6,6‐pentamethylpiperidine (PMP) [13] to give final trimethylated isomuscarine 8 as an iodide salt form in 68% yield. All analytical data including 1 H and 13 C NMR spectra of our synthetic epiallo ‐isomuscarine 8 , were fully matched with data reported in literature [13a] . This told us that the stereochemical relation of both hydroxy groups have anti ‐relationship.…”

Section: Resultssupporting

confidence: 81%

Highly Efficient and Stereoselective Mukaiyama Aldol Reaction with Chiral Aziridine‐2‐carboxaldehyde and Its Synthetic Applications

Srivastava

2021

Asian J Org Chem

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A straightforward and highly diastereoselective synthesis of β-(aziridin-2-yl)-β-hydroxy ketones was achieved by the Mukaiyama aldol reaction of optically pure 1-(αmethylbenzyl)-aziridine-2-carboxaldehyde and various enolsilanes in ZnCl 2 via a chelation-controlled transition state (98 : 2 dr and > 82% yields). These β-(aziridin-2-yl)-β-hydroxy ketones were applied for the synthesis of various alkaloids including epiallo-isomuscarine, epi-enigmol, and epi-galantinic acid.

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Section: Resultssupporting

confidence: 81%

Highly Efficient and Stereoselective Mukaiyama Aldol Reaction with Chiral Aziridine‐2‐carboxaldehyde and Its Synthetic Applications

Srivastava

2021

Asian J Org Chem

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“…With that, we found the 5 0 dAdo radical to be a weak oxidant and base, abstracting H-atoms from native substrates with a relatively higher degree Scheme 2 Reactivity of the 5 0 -deoxyadenosyl radical in water vs. enzymatic environment. While 5 0 dAdo is well known to be competent as an H-atom abstractor in radical SAM enzymes (the left side of the scheme), 17,18 it is unstable in water, undergoing an experimentally documented pathwaycyclization 20 (the product of which is shown in the right upper corner of the scheme) or, as suggested by this computational work, rybosyl-ring opening pathway 21 depicted in the right lower corner of the scheme.…”

Section: Introductionmentioning

confidence: 73%

Elucidation of factors shaping reactivity of 5′-deoxyadenosyl – a prominent organic radical in biology

Wojdyla,

Maldonado-Domínguez,

Bharadwaz

et al. 2024

Phys. Chem. Chem. Phys.

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“…The new guidelines supplement the set of existing directives, developed for predicting the major products in synthesis of monocyclic disubstituted tetrahydrofurans by the oxygen radical method. 7,14,67 The first of the new guidelines ranks the hierarchy of two similarly sized stereoinductors by the distance between the alkyl group and the alkene carbon which is being approached by the oxygen radical. This guideline states that the substituent positioned the closest to the attacked alkene carbon is the principal ( primary) inductor, guiding 5-exo-cyclization 2,3trans-and 2,4-cis-selectively.…”

Section: Discussionmentioning

confidence: 99%

Annulated and bridged tetrahydrofurans from alkenoxyl radical cyclization

et al. 2014

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4-Pentenoxyl radicals sharing two or more carbon atoms with a cycloalkane cyclize in a predictable manner stereoselectively and regioselectively to afford in solutions of bromotrichloromethane cycloalkyl-fused or -bridged 2-bromomethyltetrahydrofurans in up to 95% yield. Stereoselectivity in alkenoxyl radical ring closures arises from cumulative steric effects. The substituent positioned the closest to the alkene carbon, which is being attacked by the oxygen radical, exerts the strongest stereodirecting effect. This principal inductor guides 5-exo-cyclization 2,3-trans- or 2,4-cis-selectively. The substituent located further from the attacked π-bond is the secondary inductor. A secondary inductor in the relative trans-configuration enhances stereodifferentiation by the primary inductor; a cis-configured secondary inductor decreases this effect. A secondary inductor is not able to overrule the guiding effect of a similar sized primary inductor. Intramolecular 4-pentenoxyl radical additions to a cyclohexene-bound exo-methylene group or to endocyclic double bonds proceed cis-specifically, as exemplified by synthesis of a diastereomerically pure bromobicyclo[2.2.1]heptyl-annulated tetrahydrofuran from the verbenylethyloxyl radical. According to theory, the experimental 2,3-cis-specificity in alkoxyl radical cyclization to an endocyclic π-bond arises from strain associated with the 2,3-trans-ring closure.

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Synthesis and structural characterization of the isomuscarines

Cited by 5 publications

References 45 publications

Highly Efficient and Stereoselective Mukaiyama Aldol Reaction with Chiral Aziridine‐2‐carboxaldehyde and Its Synthetic Applications

Highly Efficient and Stereoselective Mukaiyama Aldol Reaction with Chiral Aziridine‐2‐carboxaldehyde and Its Synthetic Applications

Elucidation of factors shaping reactivity of 5′-deoxyadenosyl – a prominent organic radical in biology

Annulated and bridged tetrahydrofurans from alkenoxyl radical cyclization

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