Stereochemical Aspects of the Beckman Rearrangement of Oximes of Levoglucosenone and Its Dihydro Derivative. Enantioselective Synthesis of (+)- -Pelargonolactone

Валеев, Ф. А.; Gorobets, E. V.; Tsypysheva, I. P.; Singizova, G. Sh.; Kalimullina, L. Kh.; Safarov, M. G.; Shitikova, O. V.; Мифтахов, М. С.

doi:10.1023/b:conc.0000018110.36123.f2

Cited by 17 publications

(7 citation statements)

References 2 publications

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“…Synthesis and structure-determinations of Cyrene-based oximes A range of Cyrene-based oximes of varying leaving group ability ( pK a 16-2.85 for the conjugate acid) were synthesized. Reaction of Cyrene with HONH 2 •HCl in pyridine afforded the parent oxime 1 as a single geometrical isomer, 22 a result which reflects both steric as well as electronic effects ( Fig. 2a).…”

Section: Resultsmentioning

confidence: 98%

“…21 Cyrene readily forms an oxime which undergoes the abnormal Beckmann reaction as a result of the effects of two donor oxygen atoms on the antiperiplanar carbon, causing a Grob fragmentation. 22 Moreover, the bicyclic nature of this compound provides a rigid structure that minimizes molecular flexibility while at the same time orienting the donor oxygens so as to provide effective orbital mixing in the ground state.…”

Section: Introductionmentioning

confidence: 99%

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Structure–reactivity correlations of the abnormal Beckmann reaction of dihydrolevoglucosenone oxime

et al. 2017

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A structural, spectroscopic and computational study of a series of oximes was undertaken to investigate how geometric and structural changes relevant to the reaction coordinate for the Beckmann reaction (normal Beckmann) and Beckmann fragmentation (abnormal Beckmann) manifest in the ground state. X-ray structures of a range of oximes derived from dihydrolevoglucosan (Cyrene™; which undergoes the abnormal Beckmann reaction), in which the oxygen substituent was systematically varied were determined. As the electron demand of the OR group increased, the major structural changes included lengthening of the N-OR bond distance, and a decrease in the magnitude of the C2[double bond, length as m-dash]N-O bond angle, consistent with the changes seen for cyclohexanone oximes, which undergo the normal Beckmann reaction. However, unique to the Cyrene oximes, an increase in the length of the fissile C1-C2 bond was observed, which correlated with a decrease in the C-C 1-bond coupling constants as the electron demand of the OR substituent increased. Computational studies of Cyrene and cyclohexanone oximes using Natural Bond Orbital analysis support an electronic structure involving n → σ* and σ → σ* localized orbital interactions.

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Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Structure–reactivity correlations of the abnormal Beckmann reaction of dihydrolevoglucosenone oxime

et al. 2017

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“…Exo -amine 4 has been reported through a 4-step synthesis route starting from LGO [ 46 ], and can also be accessed from LGO by an enzymatic transamination reaction as part of a process recently awarded the Peter J. Dunn Award for Green Chemistry 2022 [ 48 , 54 ]. For scaling purposes and to get access to the endo isomer as well, we resorted to an alternative route consisting of Ni-catalyzed hydrogenation of the known oxime of Cyrene ( 3 ) [ 55 , 56 ]. This sequence was routinely scaled to 20-g scale, affording an inseparable ~6:4 mixture of diastereomers with the tentatively assigned major diastereomer being the endo isomer.…”

Section: Resultsmentioning

confidence: 99%

Green Drug Discovery: Novel Fragment Space from the Biomass-Derived Molecule Dihydrolevoglucosenone (CyreneTM)

et al. 2023

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Biomass-derived molecules can provide a basis for sustainable drug discovery. However, their full exploration is hampered by the dominance of millions of old-fashioned screening compounds in classical high-throughput screening (HTS) libraries frequently utilized. We propose a fragment-based drug discovery (FBDD) approach as an efficient method to navigate biomass-derived drug space. Here, we perform a proof-of-concept study with dihydrolevoglucosenone (CyreneTM), a pyrolysis product of cellulose. Diverse synthetic routes afforded a 100-membered fragment library with a diversity in functional groups appended. The library overall performs well in terms of novelty, physicochemical properties, aqueous solubility, stability, and three-dimensionality. Our study suggests that Cyrene-based fragments are a valuable green addition to the drug discovery toolbox. Our findings can help in paving the way for new hit drug candidates that are based on renewable resources.

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“…Syn-and anti-oximes of 1,6-anhydro-3,4-dideoxy-β-D-glycerohex-3-enopyranos-2-ylose (2) was prepared as before [7].…”

Section: Methodsmentioning

confidence: 99%

Synthesis of 2-amino derivatives of levoglucosenone

et al. 2004

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2-Amino derivatives of levoglucosenone were prepared by reaction of the 2-methanesulfonyl (or p-toluenesulfonyl) derivatives with ammonia, methylamine, or octylamine under various conditions. The analogous reaction did not occur for saturated derivative 15. The 2-amino-3,4-dihydro derivative was prepared by catalytic hydrogenation of unsaturated amine 9.Amino sugars act as structural components of many natural compounds including such large groups as mucopolysaccharides and mixed biopolymers. However, they are rarely found in the free state. As a rule, amino sugars required for organic synthesis are obtained by aminolysis of halides, sulfonates, and anhydro derivatives of monosaccharides or reduction of ketose oximes and hydrazones [1,2]. The carbohydrate levoglucosenone (1), which is prepared by cellulose pyrolysis [3], is promising for preparing unsaturated amino sugars and their derivatives. N-Containing derivatives of this sugar enone include heterocyclic products of tandem conversions [4-7], oxime 2 [8], and regioisomeric amines formed by hydroxyamination of 1,6-anhydro-3,4-dideoxy-β-D-threo-hex-3-enopyranose [9].Oxime 2 was synthesized by the literature method [8]. Furthermore, reaction of levoglucosenone with hydrazine sulfate in pyridine produced a different azomethine, hydrazone 3. Unfortunately, attempts to reduce azomethines 2 and 3 with LiAlH 4 gave products that were difficult to isolate from aqueous solutions.Alernative approaches could be based on substitution reactions, which are known to proceed difficultly in six-membered pyranose rings [1]. Nevertheless, keeping in mind the allylic position of the reaction center and the pseudoequatorial orientation of the substituted group, we studied the possibility of this approach.

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Stereochemical Aspects of the Beckman Rearrangement of Oximes of Levoglucosenone and Its Dihydro Derivative. Enantioselective Synthesis of (+)- -Pelargonolactone

Cited by 17 publications

References 2 publications

Structure–reactivity correlations of the abnormal Beckmann reaction of dihydrolevoglucosenone oxime

Structure–reactivity correlations of the abnormal Beckmann reaction of dihydrolevoglucosenone oxime

Green Drug Discovery: Novel Fragment Space from the Biomass-Derived Molecule Dihydrolevoglucosenone (CyreneTM)

Synthesis of 2-amino derivatives of levoglucosenone

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