Lythraceae Alkaloids Research Articles

Biomimetic Organocatalytic Approach to 4-Arylquinolizidine Alkaloids and Application in the Synthesis of (-)-Lasubine II and (+)-Subcosine II.

An enantioselective, biomimetic organocatalytic synthesis of 4-arylquinolizidin-2-ones, key intermediates in the synthesis of several Lythraceae alkaloids, was developed. The methodology features S-proline-mediated Mannich/aza-Michael reactions of readily available arylideneacetones and Δ1-piperideine. The total syntheses of (-)-lasubine II and (+)-subcosine II as well as the formal syntheses of structurally related Lythraceae alkaloids were achieved. The use of Δ1-pyrroline in the Mannich/aza-Michael reaction provides enantiomerically enriched 5-arylindolizidin-7-ones, which are precursors to nonopiate antinociceptive agents.

Enantioselective synthesis of (−)-lasubine II

A highly enantioselective synthesis of lythraceae alkaloid lasubine II has been achieved using organo-catalyzed Mannich reaction, Maruoka allylation, and aza-Michael addition as the key steps.

Sarusubine A, a new dimeric Lythraceae alkaloid from Lagerstroemia subcostata

A new dimeric Lythraceae alkaloid with a cyclobutane ring, sarusubine A ( 1), has been isolated from the leaves of Lagerstroemia subcostata, and the structure and stereochemistry were elucidated by spectroscopic data.

An NMR study of the Lythraceae alkaloids

Several Lythraceae alkaloids containing either a trans-fused (decinine, decodine, decaline) or a cis-fused (decamine, verticillatine, vertaline) quinolizidine ring system were examined by high-field NMR spectroscopy. One- and two-dimensional NMR techniques were used in order to assign the 1H and 13C chemical shifts. The selective 1-D TOCSY experiment was particularly helpful for resolving the 1H signals of the quinolizidine ring of some of the alkaloids. The chemical shift data combined with two-dimensional NOE experiments differentiated the cis- and trans-quinolizidine rings and provided structural information that correlated well with structures derived from molecular modelling. Copyright © 2000 John Wiley & Sons, Ltd.

Synthesis of (-)-Lasubine(I) via a Planar Chiral (eta(6)-Arene)Cr(CO)(3)] Complex.

Key steps of the synthesis of the Lythraceae alkaloid (−)-lasubine(I) are the formation of an enantiopure planar chiral arylaldehyde tricarbonylchromium complex and highly diastereoselective aza-Diels−Alder cycloaddition and intramolecular radical cyclization reactions to afford a quinolizidinone intermediate. Ketone reduction, desilylation, and decomplexation yield the enantiomerically pure product.

An NMR study of the Lythraceae alkaloids

Several Lythraceae alkaloids containing either a trans-fused (decinine, decodine, decaline) or a cis-fused (decamine, verticillatine, vertaline) quinolizidine ring system were examined by high-field NMR spectroscopy. One- and two-dimensional NMR techniques were used in order to assign the 1H and 13C chemical shifts. The selective 1-D TOCSY experiment was particularly helpful for resolving the 1H signals of the quinolizidine ring of some of the alkaloids. The chemical shift data combined with two-dimensional NOE experiments differentiated the cis- and trans-quinolizidine rings and provided structural information that correlated well with structures derived from molecular modelling. Copyright © 2000 John Wiley & Sons, Ltd.

Biosynthesis of Lythraceae Alkaloids: Incorporation of DL-{4,5-13C2, 6-14C}lysine and cis-and trans-4-(3,4-dihydroxyphenyl)-quinolizidin-2-one Into Vertine and Lythrine

DL-{4,5- 13 C 2 , 6- 14 C]Lysine is incorporated specifically, and via a symmetrical intermediate, into ring A of vertine {11} and lythrine {10}; the cis- and traans-quinolizidinones, 25 and 19, are, respectively and specifically, effective precursors for 11 and 10, and the corresponding mono-O-methyl ethers 15, 17, 21, and 23 are nor effectively utilized foralkaloid biosynthesis

Stereoselective Preparation of Acyclic syn-β-Amino Alcohols from β-Hydroxy Ketones via the Corresponding O-Benzyl Oximes

Abstract Reduction of β-hydroxy ketone O-benzyl oximes with lithium aluminum hydride in the presence of sodium or potassium methoxide afforded the corresponding syn-β-amino alcohols in highly stereoselective manner. A lythraceae alkaloid, lasubine II, was synthesized stereoselectively by applying this method.

A NEW APPROACH TO THE SYNTHESIS OF A LYTHRACEAE ALKALOID, LASUBINE II

Abstract A lythraceae alkaloid, (±)-lasubine II, is synthesized via an acyclic syn-1,3-amino alcohol which is derived stereoselectively from a β-hydroxy ketone.

Synthetic studies on Lythraceae alkaloids via (3+2)cycloaddition. II. Total synthesis of (.+-.)-decaline and (.+-.)-vertaline.

An efficient total synthesis of (±)-decaline and (±)-vertaline, lactonic biphenyl ether Lythraceae alkaloids, was achieved. The [3+2] cycloaddition of the nitrone (24) with the olefin (10), prepared via the Ullmann reaction catalyzed by a phase-transfer reagent, produced the adduct (11) which, upon treatment with methanesulfonyl chloride followed by reductive cleavage of the N-O bond, gave the isomeric quinolizidinols (13 and 14) in a one-pot operation. Through the use of inter-and intramolecular Mitsunobu reaction as an inversion procedure at C-2, 13 was converted into (±)-decaline (1). On the other hand, the cis-quinolizidinol (14) was transformed in two steps to (±)-vertaline (2).

ChemInform Abstract: SYNTHETIC STUDIES ON THE LYTHRACEAE ALKALOIDS. 11. MODEL STUDIES FOR THE SYNTHESIS OF LYTHRACINE V

Chemischer InformationsdienstVolume 15, Issue 23 Natural Products ChemInform Abstract: SYNTHETIC STUDIES ON THE LYTHRACEAE ALKALOIDS. 11. MODEL STUDIES FOR THE SYNTHESIS OF LYTHRACINE V J. QUICK, J. QUICKSearch for more papers by this authorY. KHANDELWAL, Y. KHANDELWALSearch for more papers by this authorP. C. MELTZER, P. C. MELTZERSearch for more papers by this authorJ. S. WEINBERG, J. S. WEINBERGSearch for more papers by this author J. QUICK, J. QUICKSearch for more papers by this authorY. KHANDELWAL, Y. KHANDELWALSearch for more papers by this authorP. C. MELTZER, P. C. MELTZERSearch for more papers by this authorJ. S. WEINBERG, J. S. WEINBERGSearch for more papers by this author First published: June 5, 1984 https://doi.org/10.1002/chin.198423310Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume15, Issue23June 5, 1984 RelatedInformation

Synthetic studies on lythraceae alkaloids via (3+2)cycloaddition. I. Total synthesis of some simple phenylquinolizidine alkaloids and ester alkaloids.

A general synthetic route to Lythraceae alkaloids based on a regio- and stereoselective [3+2] cycloaddition reaction has been developed. The [3+2] cycloaddition of the nitrone 5 with the olefins 14 and 26 gave the adducts 15 and 27 which, upon treatment with methanesulfonyl chloride followed by reductive cleavage of the N-O bonds and acetylation, gave the trans-quinolizidines 18 and 30 and the cis-isomers 20 and 32 in reasonable yields. The cis-isomers were converted into the simple phenylquinolizidine alkaloid, (±)-2, and the ester alkaloid, (±)-10-epi-desmethoxyabresoline (4). On the other hand, (±)-1, (±)-lasubine II (23), and (±)-abresoline (3) were synthesized efficiently from the trans-isomers, after inversion of the configuration at the C-2 position by means of the Mitsunobu reaction.

Synthetic Studies of the Lythraceae Alkaloids via [3+2] Cycloaddition Reaction

Synthetic Studies of the Lythraceae Alkaloids via [3+2] Cycloaddition Reaction

Synthetic studies on the Lythraceae alkaloids. 11. Model studies for the synthesis of lythracine V

Synthese du diacetate de methoxy-4' phenyl-4 (R-4) quinolizidinediol-1,2 a partir de R-4 quinolizidone-2 par l'intermediaire de l'epoxydation stereoselective de la R-4 deshydro-1 quinolizidine

Biosynthesis of lythraceae alkaloids: incorporation of DL-[4,5-13C2,6-14C]lysine and cis- and trans-4-(3,4-dihydroxyphenyl)-quinolizidin-2-one into vertine and lythrine

DL-[4,5-13C2,6-14] Lysine is incorporated specifically, and via a symmetrical intermediate, into ring A of vertine (3) and lythrine (6); the cis- and trans-quinolizidinones, (9) and (10), are respectively and specifically, effective precursors for (3) and (6), and the corresponding mono-O-methyl ethers (11)–(14) are not utilized for alkaloid biosynthesis.

An efficient total synthesis of (±)-decaline and (±)-vertaline

An efficient total synthesis of the Lythraceae alkaloids decaline and vertaline via the intermolecular [3+2]cycloaddition is described.

Reactions of the Lythraceae alkaloids. Regio and stereoselective methoxylations and hydroxylations of lythrine

Mercuric acetate assisted methoxylations and hydroxylations of lythrine resulted in a regio and stereoselective introduction of the substituent at the benzylic position with S-stereochemistry. The compounds obtained are thus epimeric at C13 with the naturally hydroxylated alkaloid lythridine and its derivatives. The implications of the results in planning the total synthesis of lythrine is discussed.

The biosynthesis of the Lythraceae alkaloids. I. The lysine-derived fragment

The biosynthesis of decodine (7) and decinine (9), Lythraceae alkaloids containing a trans-fused quinolizidine nucleus, was studied in intact plants of Decodonverticillatus (L.) Ell. Nonrandom incorporation of radioactivity from 14C-labelled samples of lysine, cadaverine, and Δ1-piperideine was demonstrated by partial degradation. Pelletierine did not serve as a precursor of the alkaloids. It was also shown, by means of 3H,14C-labelled tracers, that the alkaloids are derived from L-lysine whereas pipecolic acid, which is present in the plant, is derived from D-lysine.

The biosynthesis of the Lythraceae alkaloids. II. The phenylalanine-derived fragments

Label from [1-14C]-, [2-14C]-, [3-14C]-, and [1,3-14C2]phenylalanine is incorporated non-randomly into the Lythraceae alkaloids, decodine and decinine, in Decodonverticillatus. The incorporation pattern, determined by chemical degradation of the alkaloids, demonstrates incorporation of two intact C6—C3 units.

ChemInform Abstract: THE β‐METHOXYETHOXYMETHYL PROTECTING GROUP IN ALKALOID SYNTHESIS. SYNTHESIS OF ABRESOLINE

AbstractDas Phenol (I) wird mit Methoxyethoxymethylchlorid (MEM‐Cl) (II) zum Chinolizidon (III) verethert und anschließend zum Alkohol (IV) stereoselektiv reduziert.