Structure of murrayacine

Chakraborty, D. P.; Das, Koushik

doi:10.1039/c19680000967

Cited by 9 publications

(13 citation statements)

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“…Treatment of 7 with equimolar amounts of CSA in toluene at 100 8C results in an isopropenyl-to-isopropylidene isomerization of the double bond and leads to the thermodynamically more stable isocyclomahanimbine (33) which has not been identified in nature so far (Scheme 13). [34a] Epoxidation of the isopropenyl double bond of compound 7 using Oxone (potassium peroxymonosulfate) in acetone [41] followed by reduction with lithium aluminum hydride afforded murrayazolinine (10). The spectroscopic data of compound 10 were in full agreement with those reported for the natural product.…”

Section: Introductionmentioning

confidence: 58%

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Efficient Construction of Pyrano[3,2‐a]carbazoles: Application to a Biomimetic Total Synthesis of Cyclized Monoterpenoid Pyrano[3,2‐a]carbazole Alkaloids

Hesse¹,

Gruner²,

Kataeva³

et al. 2013

Chemistry A European J

113

106

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We have developed a highly efficient route to 2-hydroxy-3-methylcarbazole (1) via a palladium-catalyzed construction of the carbazole skeleton. Using 1 as relay compound, different methods for annulations of pyran rings by reaction with terpenoid building blocks have been tested. The Lewis acid promoted reaction of 1 with prenal (21) opened up an efficient route to girinimbine (3) and the corresponding reaction with citral (25) afforded mahanimbine (5). Oxidation of compounds 3 and 5 provided murrayacine (4) and murrayacinine (6). Following the biogenetic proposal, mahanimbine (5) has been exploited for efficient biomimetic syntheses of the cyclized monoterpenoid pyrano[3,2-a]carbazole alkaloids cyclomahanimbine (7), mahanimbidine (8) and bicyclomahanimbine (9). The interconversions of 5, 7, 8 and 9 are described and mechanistic implications are discussed. Structural assignments are unambiguously verified by X-ray crystal structure determinations. Moreover, cyclomahanimbine (7) was transformed into murrayazolinine (10) and exozoline (11).

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Section: Introductionmentioning

confidence: 58%

“…from Murraya koenigii and from Clausena heptaphylla 5c. 10, 11 Geranylation of 1 followed by pyran annulation to mahanimbine ( 5 ) is an alternative pathway in the biogenesis of these alkaloids. The first isolation of (+)‐mahanimbine ( 5 ) was reported in 1966 by Chakraborty et al.…”

Section: Introductionmentioning

confidence: 99%

Efficient Construction of Pyrano[3,2‐a]carbazoles: Application to a Biomimetic Total Synthesis of Cyclized Monoterpenoid Pyrano[3,2‐a]carbazole Alkaloids

Hesse¹,

Gruner²,

Kataeva³

et al. 2013

Chemistry A European J

113

106

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“…This second approach started with the oxidation of 9 a by using DDQ to obtain the corresponding aldehyde murrayacine ( 24 ) in 96 % yield (Scheme ) . Boc‐Protection of the carbazole nitrogen atom of 24 followed by reduction of the carbaldehyde to a hydroxymethyl group and activation of the latter as para ‐nitrobenzoate provided 25 in 87 % yield over three steps.…”

Section: Resultsmentioning

confidence: 99%

“…This second approachs tarted with the oxidation of 9a by using DDQ to obtain the corresponding aldehyde murrayacine (24) [29] in 96 %yield (Scheme 9). [6c, l] Boc-Protection of the carbazole nitrogen atom of 24 followed by reduction of the carbaldehydet oahydroxymethyl group and activation of the latter as para-nitrobenzoate provided 25 in 87 %y ield over three steps.C oupling of para-nitrobenzoate 25 and 8a by application of the conditions described above directly provided 6; thus, biscarbazole 6 was obtained in nine steps and 15 %o verall yield based on commercially available compounds.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Methylene‐Bridged Biscarbazole Alkaloids by using an Ullmann‐type Coupling: First Total Synthesis of Murrastifoline‐C and Murrafoline‐E

Kutz

Börger

Schmidt

et al. 2016

Chemistry A European J

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We describe the total synthesis of methylene-bridged biscarbazole alkaloids by using a late-stage Ullmann-type coupling of fully functionalised carbazole subunits. The carbazole derivatives were synthesised via a sequence of palladium(0)- and palladium(II)-catalysed coupling reactions. Our approach has provided bismurrayafoline-A, bismurrayafolinol, chrestifolines B-D, and the first total synthesis of murrastifoline-C and murrafoline-E.

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“…Thus, total synthesis of chrestifoline-B (193) In addition, the Furukawa research group in 1988 isolated murrafoline-E (196) from the root bark of Murraya euchrestifolia Hayata. [146] Total synthesis of 184 was started from 192 a, which after several steps including oxidation, [147] Boc-protection, and reduction afforded para-nitrobenzoate (195). The latter after coupling reaction with 186 via Ullmann reaction conditions (Cu-catalyzed reaction) gave murrafoline-E (196).…”

Section: Cu (I) Complexesmentioning

confidence: 99%

Catalytic Function of Cu (I) and Cu (II) in Total Synthesis of Alkaloids

et al. 2021

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Recently, Cu-catalyzed carbon-carbon and carbon (sp 2 )-nitrogen bond formation have attracted much attention. Nowadays, they are widely being applied to the total synthesis of an extensive assortment of natural products with complex structures. Natural products chemistry is a discrete part of chemical research, which has been significant in the history of chemistry, the sourcing of substances in early preclinical drug discovery research, pharmacology and discovery of folk medicine. Alkaloids are a class of natural product that contains at least one nitrogen atom. They have diverse and important physiological effects on humans and other animals. In fact, as many as one-quarter of higher plants are estimated to contain alkaloids, of which several thousand (approximately 12000) different types have so far been identified. In this review, we try underscore the total synthesis of naturally occurring alkaloids in which Cu-promoted reaction is at least one of the vital step. Indeed, in this comprehensive review, the impact of Cu-catalyzed cross-coupling reactions in the total synthesis of natural products with a prominence on the evolution of strategies due to copper catalysis will be generally surveyed.

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Structure of murrayacine

Cited by 9 publications

References 0 publications

Efficient Construction of Pyrano[3,2‐a]carbazoles: Application to a Biomimetic Total Synthesis of Cyclized Monoterpenoid Pyrano[3,2‐a]carbazole Alkaloids

Efficient Construction of Pyrano[3,2‐a]carbazoles: Application to a Biomimetic Total Synthesis of Cyclized Monoterpenoid Pyrano[3,2‐a]carbazole Alkaloids

Synthesis of Methylene‐Bridged Biscarbazole Alkaloids by using an Ullmann‐type Coupling: First Total Synthesis of Murrastifoline‐C and Murrafoline‐E

Catalytic Function of Cu (I) and Cu (II) in Total Synthesis of Alkaloids

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