The structure of regalamine

Yusupov, M. K.; Abdullaeva, D. A.; Aslanov, Kh. A.; Sadykov, A. S.

doi:10.1007/bf00571217

Cited by 3 publications

(6 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Next, substrates bearing Me, ethyl and allyl groups at the 2position of enone ring (R 2 ) were examined (Table 3, entries [13][14][15]. Substrate 1 m bearing a Me group afforded 2 m in 81 % yield with reasonable diastereoselectivity (syn: anti = 6 : 1) with a long reaction time required for consumption of the starting material.…”

Section: Resultsmentioning

confidence: 99%

“…Our group is currently working on the application of this reaction to the synthesis of other complex proaporphine alkaloids and development of asymmetric version of this reaction using chiral Lewis or Brønsted acids. 13 C NMR) at 25 °C with tetramethylsilane (δ = 0.0 ppm) as an internal standard. The data are reported as follows: chemical shift in ppm (δ), multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet), integration, and coupling constant (Hz).…”

Section: Discussionmentioning

confidence: 99%

“…IR spectra of samples were measured with a JASCO FT/IR-4100 spectrometer. 1 H NMR and13 C NMR spectra were recorded with a Bruker Avance III 600 spectrometer operating at 600 MHz (150 MHz for…”

mentioning

confidence: 99%

See 2 more Smart Citations

Development of TfOH‐Catalyzed Spirocyclization by Intramolecular Friedel‐Crafts‐type 1,4‐Addition: Application to the Total Synthesis of the Unusual Proaporphine Alkaloid (±)‐Misrametine

Yoshida

Hidaka

Fukami

et al. 2022

Chemistry A European J

View full text Add to dashboard Cite

An effective method was developed for TfOHcatalyzed construction of spiroindanes and spirotetralines containing an all-carbon quaternary stereocenter. Intramolecular Friedel-Crafts-type 1,4-addition of the substrates which were di-or trimethoxybenzene and 2-cyclohexenone linked by an alkyl chain proceeded smoothly in the presence of 30 mol % of TfOH. A variety of spiroindanes and spirotetra-lines were obtained with moderate to excellent yield by this method. The reaction was successfully applied in the first total synthesis of the unusual proaporphine alkaloid (�)misrametine, which included the gram-scale spirocyclization and selective O-demethylation used KCN in DMSO condition as key steps.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Development of TfOH‐Catalyzed Spirocyclization by Intramolecular Friedel‐Crafts‐type 1,4‐Addition: Application to the Total Synthesis of the Unusual Proaporphine Alkaloid (±)‐Misrametine

Yoshida

Hidaka

Fukami

et al. 2022

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…Pentacyclic homoproaporphine alkaloids (e.g., 1 – 7 ; Figure ) are an important type of tetrahydroisoquinoline-based bioactive natural products, featuring a unique oxa-benzobicyclo[3.3.1]nonane core structure and a bridged spirocyclic ring bearing an all-carbon quaternary stereocenter The family of pentacyclic homoproaporphine alkaloids include more than 10 members, and among them, (+)-regalamine ( 2 ) and (+)-kesselridine ( 3 ) were the first two members isolated from the Eurasian species Colchicum kesselringii . Some of them have been found to have anticholinesterase activitity .…”

mentioning

confidence: 99%

“…= +93 ( c 1.5, MeOH))] in 60% yield (two steps). Transformation of the ketal unit of 1 to a hemiketal by treatment with 5% H 2 SO 4 generated (+)-regalamine ( 2 ) [[α] 25 D = +43.8 ( c 1.92, MeOH) (lit . = +33 ( c 1.93, MeOH))] in 95% yield.…”

mentioning

confidence: 99%

Enantioselective Total Syntheses of Pentacyclic Homoproaporphine Alkaloids

Yang

Chen

et al. 2020

Org. Lett.

View full text Add to dashboard Cite

Herein we report the first enantioselective total syntheses of pentacyclic homoproaporphine alkaloids by means of a route, which includes a tandem retro-oxa-Michael addition and nucleophilic substitution to generate the oxa-benzobicyclco[3.3.1]nonane core structure, a Pictet–Spengler cyclization to construct the fused B and C rings, and sequential Baeyer–Villiger oxidation and pinacol-type cyclization to install the hydroxyl-lactol moiety of D ring. With this unified route, six pentacyclic homoproaporphine alkaloids have been synthesized enantioselectively.

show abstract

Gold‐Catalyzed Annulations of 2‐Alkynyl Benzaldehydes with Vinyl Ethers: Synthesis of Dihydronaphthalene, Isochromene, and Bicyclo[2.2.2]octane Derivatives

Malhotra

Liu

Mashuta

et al. 2013

Chemistry A European J

View full text Add to dashboard Cite

With the suitable selection of a gold catalyst as well as the appropriate control of the reaction conditions, various new gold‐catalyzed cyclizations of 2‐alkynyl benzaldehyde with acyclic or cyclic vinyl ethers have been developed. Acetal‐tethered dihydronaphthalene and isochromenes were obtained from the reactions of 2‐alkynyl benzaldehydes with acyclic vinyl ethers under mild conditions. And, more interestingly, the gold‐catalyzed reactions of 2‐alkynyl benzaldehyde with a cyclic vinyl ether afforded the bicyclo[2.2.2]octane derivative involving two molecules of cyclic vinyl ethers. These products contain interesting substructures that have been found in many biologically active molecules and natural products. In addition, a gold‐catalyzed homo‐dimerization of 2‐phenylethynyl benzaldehyde 1 a was observed when the reaction was carried out in the absence of vinyl ether, affording a set of separable diastereomeric products. Plausible mechanisms for these transformations are discussed; a gold‐containing benzopyrylium was regarded as the crucial intermediate by which a number of these new transformations took place.

show abstract

The structure of regalamine

Cited by 3 publications

References 6 publications

Development of TfOH‐Catalyzed Spirocyclization by Intramolecular Friedel‐Crafts‐type 1,4‐Addition: Application to the Total Synthesis of the Unusual Proaporphine Alkaloid (±)‐Misrametine

Development of TfOH‐Catalyzed Spirocyclization by Intramolecular Friedel‐Crafts‐type 1,4‐Addition: Application to the Total Synthesis of the Unusual Proaporphine Alkaloid (±)‐Misrametine

Enantioselective Total Syntheses of Pentacyclic Homoproaporphine Alkaloids

Gold‐Catalyzed Annulations of 2‐Alkynyl Benzaldehydes with Vinyl Ethers: Synthesis of Dihydronaphthalene, Isochromene, and Bicyclo[2.2.2]octane Derivatives

Contact Info

Product

Resources

About