bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on electron transfer as mechanistic concept for [4 + 2] cycloadditions, 2. Cycloadditions of 2,3‐bis(dimethylaminomethylene)bicyclo[2.2.1]heptane and 2,3‐bis(dimethylaminomethylene)bicyclo[2.2.2]octane with electron‐deficient olefins
Authors: Rese Michael , Dern Mechthild , Lücking Karin , Sustmann Reiner 
Published: July 2007

AbstractElectron transfer as initiating step in [4 + 2] cycloadditions was studied with 2,3‐bis(dimethylaminomethylene)bicyclo‐[2.2.1]heptane (1) and 2,3‐bis(dimethylaminomethylene)bicyclo[2.2.2]octane (2) as models. These dienes, having the necessary synperiplanar configuration for a concerted [4 + 2] cycloaddition were allowed to react with dienophiles of increasing acceptor capacity. Slightly activated alkenes like methyl acrylate and acrylonitrile undergo smooth cycloaddition in contrast to the corresponding open‐chain dienes where cycloaddition with these dienophiles could not be observed. The use of dimethyl fumarate and dimethyl maleate lead to identical cycloaddition products due to an isomerization of dimethyl maleate catalyzed by 1 and 2. Fumaronitrile and maleonitrile proved to be stable under the reaction conditions and lead to different stereoisomers in the cycloaddition to 2. The introduction of three and four acceptor groups, different combinations of cyano and methoxycarbonyl groups, leads to a sudden increase in reactivity towards 1 and 2. At the same time the cycloadditions are no longer stereospecific in those cases where they could be checked, and radical ions could be detected either by ESR spectroscopy or by stopped‐flow visible spectroscopy. This applies in particular to dichloromethane as solvent. Stopped‐flow measurements in combination with a rapid‐scan unit reveals a transient absorption at λ ∽ 420 nm in acetonitrile for 1,1‐dicyano‐2,2‐bis(methoxycarbonyl)ethene and dimethyl dicyanofumarate as dienophiles which is ascribed to zwitterionic intermediates by a comparison with related systems. The cycloadditions of TCNE to 1 and 2 lead to thermally unstable adducts in both cases. Electron transfer was not only observed in solution but could also be detected in the isolated solid products, in particular if they were placed in a polar environment like KBr where complete dissociation in radical ions seems to take place. The relevance of these studies for the mechanism of Diels‐Alder reactions is that suitable model systems can be constructed where electron transfer can be observed. Due to the loss of stereospecificity in these cases it is concluded that complete electron transfer is not the principal mechanism of these [4 + 2] cycloadditions which in their majority occur with retention of stereochemistry in the reactants.
Efficient and convergent synthesis of (R)‐(−)‐10‐methyltridecan‐2‐one, the sex pheromone of the spotted cucumber beetle, by iron‐mediated chirality transfer
Authors: Enders Dieter , Jandeleit Bernd 
Published: July 2007

AbstractThe synthesis of (R)‐(−)‐10‐methyltridecan‐2‐one, the female sex pheromone of the southern corn root worm (Diabrotica undecimpunctata howardi Barber) [(R)‐1] in high enantiome‐ric purity (ee ≥ 99%) and excellent overall yield (75%, five steps) is described. In the crucial step the stereogenic center is generated by nucleophilic addition of allyltrimethylsilane to an enantiopure planar chiral (π‐allyl)tetracarbonyl‐iron(1 + ) complex.
Asymmetric michael additions via SAMP/RAMP hydrazones enantioselective synthesis of 2‐substituted 4‐oxophosphonates
Authors: Enders Dieter , Wahl Heiner , Papadopoulos Kyriakos 
Published: July 2007

AbstractAsymmetric Michael addition of lithiated methyl ketone SAMP hydrazones (S)‐3 to a variety of alkenylphosphonates (E)‐2 followed by oxidative cleavage of the 1,4‐adducts (S,S)‐4 by ozonolysis afforded 2‐substituted 4‐oxophosphonates (S)‐5 in usually moderate to very good overall yields (14–77%) and with mostly high enantiomeric excesses (ee = 20–>95%). In addition, asymmetric Michael Michael tandem additions were carried out in good overall yields by trapping the intermediate lithio phosphonate anions with alkenylphosphonate or enoate Michael acceptors.
[4+ + 2] Cycloadditions with an N‐Methyl‐4H‐pyrazolium cation as electron‐deficient diazadiene system
Authors: Frenzena Gerlinde , Gerninghaus Christian , Meyer‐Dulheuer Christiane , Paulus Erich F. , Seitz Gunther 
Published: July 2007

Abstract3,6‐Diphenyl‐1,2,4,5‐tetrazine (6) reacts with dimethoxycarbene (7), generated from the 1,3,4‐oxadiazoline 8, to yield the 4H‐pyrazole 10. This is alkylated to the N‐methyl‐4H‐pyrazolium tetrafluoroborate 12 in high yield. The alkylated, cationic azine system of 12 serves as electron‐deficient diene in a [4+ + 2] cycloaddition with inverse electron demand and reacts diastereoselectively with several cyclic olefins as electron‐rich dienophiles. The initially formed cationic [4+ + 2] adduct, e.g. 15, is unstable and rearranges probably via 16 to a racemic phthalazinecarboxylic ester of type 17. The crystal structures of the epoxyphthalazinecarboxylic ester 25 and of the trans‐annulated cycloocta[d]pyridazine 27 were determined by X‐ray diffraction. In contrast to the cyclic olefins, cyclooctyne (28) reacts with the pyrazolium cation 12 to yield the cyclooctapyridiazinium tetrafluoroborate 30 via the cycloadduct 29.
Chiral lactols, XIII. On the determination of the absolute configuration of aromatic cyanohydrins and structurally related compounds
Authors: Noe Christian R. , Knollmüller Max , Gärtner Peter , Katikarides Elias , Gaischin Larissa , Völlenkle Horst 
Published: July 2007

AbstractSynthesis and conformational analysis of diastereomeric acetals 4–7 of aromatic cyanohydrins and structurally related compounds are described. Based on 1H‐NMR spectroscopic and X‐ray data it is shown that the absolute configuration of such compounds can be assigned according to a method, which has been presented previously for secondary arylalkyl alcohols.
Zum konzertierten oder nichtkonzertierten Verlauf von Reaktionen; Thermolyse von Dispiro[2.2.2.2]deca‐4,9‐dien
Authors: Roth Wolfgang R. , Unger Christian 
Published: July 2007

Concerted and Nonconcerted Reaction Path; Thermolysis of Dispiro[2.2.2.2]deca‐4,9‐dieneThe enthalpy profile for the equilibrium 1 ⇄ 2 ⇄ 3 has been determined by oxygen trapping. From the oxygen dependence at low (0.0005–0.2 bar) and high pressure (1–180 bar) between 130 and 190°C the enthalpy wells of the diradicals 3 and 2 have been derived (3 17.1, 2 3.7 kcal · mol−1). The observation of a nonconcerted path for the equilibrium 1 ⇄ 3 is important with respect to the understanding of the controlling factor of the concerted and nonconcerted path of a reaction. The existence of a favourable potential energy path obviously is not of prime importance.
Synthesis of medium and large ring compounds, XXXIX. Stereoselective synthesis of both enantiomers of 13‐tetradecanolide by ring enlargement with different chiral building blocks and olfactory comparison with (12R)‐(+)‐ and (12S)‐(−)‐12‐methyl‐13‐tridecanolide
Authors: Kraft Philip , Tochtermann Werner 
Published: July 2007

AbstractStarting from a cycloalkanone and the chiral building blocks 2 or 3 both enantiomers of 13‐tetradecanolide (1, n = 14) were prepared by ring‐enlargement reactions. Cycloundeca‐none (4) was α‐alkylated with the protected hydroxy halide 2 derived from (S)‐(−)‐methyl lactate. Acid‐catalyzed cyclization, oxidative cleavage of the enol ether double bond by PCC, and reduction of the carbonyl group via a tosylhydrazone led to the (S)‐configured target molecule (+)‐8 (98.0% ee), thus indicating the sequence proceeded with clean retention of configuration. Likewise, the naturally occurring (R)‐enantiomer (−)‐8 (>99.8% ee) was synthesized from cyclodecanone (9) and the chiral building block 3. Aided by CD conformational analysis the olfactory properties of both enantiomers were compared with those of the regioisomers (12R)‐( + )‐ and (12S)‐(−)‐12‐methyl‐13‐tridecanolide previously prepared by the same method.
Synthesis of epimeric pure spiro N,S‐acetals of L‐menthone
Authors: Altenbach Hans‐Josef , Roth Peter R. , Brauer David J. 
Published: July 2007

AbstractBy acetalisation of L‐menthone (2) with mercaptoacetic acid and derivatives of benzylamine, the spirocyclic N,S‐acetals 3 were obtained as single diastereomers. The reaction of an epimeric mixture of unsubstituted thiazolidinones 4 with acetic anhydride or allyl iodide afforded homochiral N‐acetyl (5) or N‐allyl N,S‐acetals (6), respectively. The configuration of the new stereogenic centres were proven by X‐ray crystallography.
Regioselective monometalation of 2,5‐pyridinedicarboxamides with (2,2,6,6‐tetramethylpiperidino)magnesium chloride (TMPMgCI)
Authors: Schlecker Wolfgang , Huth Andreas , Ottow Eckhard , Mulzer Johann 
Published: July 2007

AbstractThe 2,5‐pyridinecarboxamides 9–15 were synthesized in one or two steps from diester 1 by addition of an excess of dimethylaluminium amide or successive addition of two different dimethylaluminium amides with or without intermediate workup. For the carboxamides 16 and 17 this method failed; they were, however, available by other procedures. Metalation of the carboxamides 9–17 with TMPMgCI and subsequent reaction with electrophiles led to the 2,3,5‐ and 2,4,5‐substituted pyridines 9a/b‐17a/b, 18 and 19 with regioselectivities ranging from predominant 4‐substitution to complete 3‐substitution.
Macrocyclic (1,3)‐ and (1,4)‐benzena‐(1,4)‐piperazinacyclophanes
Authors: Huuskonen Juhani , Schulz Jürgen , Rissanen Kari 
Published: July 2007

AbstractNew large, up to 45‐membered macrocycles were synthesised from piperazine and m‐ and p‐2,6‐bis(bromomethyl)xylene under high dilution conditions. X‐ray structures of compounds 3a, 4a, 5a, and 8b were determined. Surprisingly, none of the macrocycles prepared showed any inclusion properties towards small guest molecules. Instead, the compounds were found to self‐organize during the packing process into larger structures due to the complementary of the molecular skeletons. In the crystalline state 3a forms nets, where the macrocycles are bound by HCH…︁N interactions to each other. 4a exits in a dimeric structure, which, in turn, further extends to a sheet structure. The positively charged phane 8b (di‐dihydrochloride salt) adopts a chair‐chair conformation, confirming that protonation of the N atoms does not change the conformation.
Dimethyldioxirane epoxidation of chalcone and isoflavone glycoside acetates
Authors: Adam Waldemar , Jekõ József , Lévai Albert , Nemes Csaba , Patonay Tamás 
Published: July 2007

AbstractEpoxides of chalcone and isoflavone glycoside acetates were synthesized in high yields and under mild conditions by using dimethyldioxirane. No enantiofacial selectivity was observed during the epoxidation of the enone system.
Acetonitrile inclusion complexes of piperazine‐based macrocycles
Authors: Huuskonen Juhani , Rissanen Kari 
Published: July 2007

AbstractNew piperazine‐based macrocycles with single small cavities were prepared by using high dilution technique. The inclusion of acetonitrile into the cavity (7, 8) or clathrate formation (3) was studied by 1H‐NMR spectroscopy in solution and by X‐ray diffraction in the crystalline state. The cycle 3 forms a molecular cleft, a molecular pocket, where the acetonitrile molecule is held by four weak N…︁H interactions reinforcing the clathrate formation. The cycles 7 and 8 contain a rigid cavity for an exact sterical fit with the methyl group of a linear compound like acetonitrile. The acetonitrile inclusion complex with 7 proved to be stable under normal conditions and was studied by means of thermogravimetry. It is stable up to 80°C and the breakdown is complete when the temperature is raised over 120°C. Solid‐state IR studies show a shift of the cyano band of 5 cm−1 to smaller wave numbers when compared with free acetonitrile. The acetonitrile methyl group is shielded and in the 1H‐NMR spectrum its signal is shifted to δ = 1.85.
Studies on the constituents of the stems of Tinospora tuberculata, V. Isolation and structure elucidation of the new furanoid diterpene glucoside borapetoside H
Authors: Fukuda Naomichi , Yonemitsu Michiko , Kimura Takeatsu 
Published: July 2007

AbstractThe new diterpene glucoside borapetoside H (1) was isolated from the fresh stems of Tinospora tuberculata Beumée (Menispermaceae). Its structure as 2‐O‐β‐D‐glucopyranosylborapetoside B was elucidated on the basis of chemical and spectroscopic findings.
Organofluorine compounds and fluorinating agents, 15. O‐difluoromethylations of monosaccharides by trifluoromethylzinc bromide
Authors: Miethchen Ralf , Hein Martin , Naumann Dieter , Tyrra Wieland 
Published: July 2007

Abstract1,2:3,4‐Di‐O‐isopropylidene‐α‐D‐galactopyranose (1), methyl 2‐O‐(cyclohexylcarbamoyl)‐3,4‐O‐(2,2,2‐ trichloroethylidene)‐α‐D‐altropyranoside (4), methyl 4,6‐O‐benzylidene‐2‐O‐to‐syl‐α‐D‐glucopyranoside (6), and methyl 4,6‐O‐benzylidene‐α‐D‐glucopyranoside (8) were O‐difluoromethylated with tri‐fluoromethylzinc bromide (ZnBrCF3. 2 CH3CN) in a convenient procedure giving the difluoromethyl ethers 2, 5, 7, 9, and the bis(difluoromethyl) ether 10 in moderate yields. The 6‐O‐difluoromethyl‐1,2:3,4‐di‐O‐isopropylidene‐ α‐D‐galacto‐pyranose (2) was deprotected by treatment with aqueous tri‐fluoroacetic acid forming 6‐O‐difluoromethyl‐D‐galactopyranose (3).
Carbenes in constrained systems, 3. Solid‐State photolysis of cycloheptane‐ and cyclooctanespirodiazirine within cyclodextrins and zeolites
Authors: Kupfer René , Brinker Udo H. 
Published: July 2007

AbstractInclusion complexes of cycloheptanespirodiazirine (1) and cyclooctanespirodiazirine (8) in α‐, β‐, and γ‐cyclodextrin, and faujasite type zeolites (NaX and NaY), have been prepared. The guest‐host complexes (1‐ and 8@CD and 1‐ and 8@zeolite) were irradiated with UV light in the solid state and the reaction products were separated from the host and analyzed. Product ratios from photolysis of complexes were compared with those obtained from pure compounds and in solution. Cycloheptanespirodiazirine (1) gives cycloheptene (2), bicyclo[4.1.0]heptane (3), and methylenecyclohexane (4). Photolysis products from cyclooctanespirodiazirine (8) are cyclooctene (9), bicyclo[3.3.0]octane (10), and bicyclo‐[5.1.0]octane (11). 10 results from a 1,5‐C–H insertion reaction of the carbene derived from 8. As the cavity size of the cyclodextrins becomes larger, the formation of 10 seems to increase. In β‐cyclodextrin and in non‐polar solvents substantial amounts of azine were found. In addition to hydrocarbons, photolyses in zeolites afforded alcohols and small amounts of the corresponding ketones.
2,5‐dichloropentacyclo[4.3.0.02,5.03,8.04,7]non‐3‐ene: Generation and trapping of a homocubene and ab initio mo calculations on this and related molecules
Authors: Rosendorfer Karin , Jarosch Oliver , Polborn Kurt , Szeimies Günter 
Published: July 2007

AbstractReaction of bromotrichlorohomocubane 8 with MeLi in the presence of anthracene, 9,10‐dimethoxyanthracene, 1,2,3‐tri‐methylisoindole, diphenylisobenzofuran, and 2,5‐dimethyl‐furan furnished Diels‐Alder adducts of the title compound 2,5‐dichlorohomocubene 7 in reasonable yields. Adduct 14a was dechlorinated by reduction with Na in tert‐butyl alcohol to afford 14b. This compound could be selectively isomerized by AgBF4 to 20 and by the rhodium(I) complex 22 to a sensitive intermediate which could be reduced to 25. The structures of adduct 15a and of 14b were confirmed by X‐ray analysis, ensuring that bridgehead olefin 7 had been trapped. Ab initio MO calculations show that 7 is lower in energy than 11 and 12. The extension of the MO calculations to all parent homocubenes (2, 3, 26, 27, 28) and to dehydrohomocubanes 6 and 29 was carried out to obtain information on their relative energies, their structures, and their singlet‐triplet energy separation.
New anthranilic and methylsulfonylpropenoic acid amides from thai Glycosmis species
Authors: Hofer Otmar , Zechner Gabriela , Vajrodaya Srunya , Lutz Gerda , Greger Harald 
Published: July 2007

AbstractFive new methylsulfonylpropenamides were isolated from different Glycosmis species collected in Thailand. Four of these derivatives contain 4‐geranyloxy‐3‐hydroxy‐substituted phenethylamine moieties, Sakerine (1) has a simple geranyloxy side chain; sakerone (2), sakerol (3), and dihydroisosakerol (4) are characterized by different states of oxidation in the geranyloxy residue. Methylgerambullal (5) contains a 4‐geranyloxy‐substituted phenethylamine unit with a terminal formyl group. Two additional amides, doisuthine (6) and methoxydoisuthine (7), exhibit the structures of N‐methylanthranilic acid amides with phenethylamine and p‐methoxyphenethylamine as amine components. All structures were elucidated by IR, UV, 1H‐, 13C‐, 2D‐NMR spectroscopy, mass spectrometry, and CD spectroscopy.
Influence of conformational factors on acid‐catalyzed cyclizations of germacranolides: Molecular structure of the cyclization products of gallicin and 8α‐hydroxygallicin (shonachalin a)
Authors: Marco J. Alberto , Sanz‐Cervera Juan F. , García‐Lliso Vicente , Domingo Luis R. , Carda Miguel , Rodríguez Santiago , López‐Ortiz Fernando , Lex Johann 
Published: July 2007

AbstractAcid‐catalyzed cyclization of the natural germacranolide gallicin (8) yielded, among other products, the 1,4‐epoxyeudes‐manolide 9, which has a trans‐fused decaline system. Under the same conditions the closely related germacranolide shonachalin A (8α‐hydroxygallicin) (3) cyclized to the eudesmanolide 4 with a cis fused decaline system. The structures of these cyclization products were secured by means of chemical correlations and X‐ray diffraction analyses.
Synthetic routes to 1,4‐difunctionalized cycloheptenes
Authors: Maier Martin E. , Langenbacher Diane , Rebien Frank 
Published: July 2007

AbstractTwo routes to 1,4‐difunctionalized cycloheptenes are described. The first one is based on a fluoride‐induced fragmentation reaction of the bicyclic [3.2.0]heptanesilyl monosulfate 10. This compound in turn was prepared by a ketene‐cyclopentene cycloaddition route. An alternative strategy took advantage of a ring‐closing metathesis (RCM) reaction of the diolefin 18 with the ruthenium catalyst 21. This reaction proved to be reliable even on a larger scale and allowed the isolation of the cycloheptene 19a in reasonably good yield.
Syntheses and CD studies of optically active substituted 1,3,4,5‐tetrahydro‐2H‐1,5‐benzodiazepin‐2‐ones
Authors: Malik Farnaz , Hasan Mashooda , Khan Khalid Mohammed , Perveen Shahnaz , Snatzke Günther , Duddeck Helmut , Voelter Wolfgang 
Published: July 2007

AbstractA route to optically active variously substituted 4‐methyl‐ and 4‐methyl‐7‐substituted 1,3,4,5‐tetrahydro‐2H‐1,5‐benzo‐diazepin‐2‐ones as analogues of commercially available Lofendazam (7‐chloro‐5‐phenyl‐1,3,4,5‐tetrahydro‐2H‐1,5‐benzodiazepin‐2‐one, 1) was developed. Fortyone variously substituted optically active compounds having the same configuration were prepared and the UV and CD spectra of the parent compounds bearing no additional substitution in the benzene ring are discussed.
Acid‐catalysed rearrangement of tetracyclo[4.3.0.02,9.04,8]nonane skeleton to substituted brendene derivatives
Authors: Mlinarić‐Majerski Kata , Kragol Goran , Šindler‐Kulyk Marija , Pavlović Dražen 
Published: July 2007

AbstractThe synthesis of 2‐exo‐substituted brendene derivatives 3a, 5a and 6 as well as 2,5‐disubstituted brendene derivative 7 is described, starting from the readily available tetracyclo‐[4.3.0.02,9.04,8]nonanone 1. The cationic rearrangement reactions of tetracyclic skeleton of 1 and 2 have been studied. The mechanism of these reactions is discussed. The preparation of inaccessible exo‐alcohol 2a by reduction of ketone 1 is presented.
Resolution of racemic 1‐azaadamantane derivatives by pig liver esterase catalysis
Authors: Mölm Detlef , Risch Nikolaus 
Published: July 2007

AbstractThe first kinetic resolution of racemic 1‐azaadamantane derivatives with PLE led to the enantiomers (−)‐1 and (−)‐2. An unexpected formation of 3 from 1 in aqueous solution was observed.
cis/trans‐ozonides of cycloolefins
Authors: Griesbaum Karl , Ball Volker , Beck Johannes , McCullough Kevin 
Published: July 2007

AbstractOzonolyses in pentane of the unsubstituted cycloolefins having eleven‐, twelve‐, fourteen‐ and sixteen‐membered rings (1b‐e) and of cyclohexadecen‐8‐one (12) gave the corresponding cis‐ (2b‐e; cis‐15a) and trans‐ozonides (3b‐e; trans‐15a), whereas cyclodecene (1a) gave only the corresponding cis‐ozonide (2a). Ozonolyses on polyethylene of the dimethyl‐substituted cycloolefins bearing fourteen‐ and sixteen‐membered rings (7b, c) also afforded cis‐ and trans‐isomeric ozonides (8, 9), whereas from the twelve‐membered ring (7a) only the corresponding cis‐ozonide (8a) was formed.
Electrophilic reactions of the dibenzo[a,d]tropylium ion
Authors: Henninger Joachim , Mayr Herbert , Patz Matthias , Stanescu Michaela Dina 
Published: July 2007

AbstractThe kinetics of the hydride transfer reactions of the dibenzo‐tropylium ion (2) with dimethylphenylsilane (5) and triphenylsilane (6) were used to determine its electrophilicity parameter E = ‐0.71. The nucleophiles 7–9 react 10–40 times faster with 2 than expected from the linear free energy relationship (1), probably due to the formation of a ‐stabilized carbocation (e.g. 15). A detailed investigation of the reaction of 2 with isobutene (4) shows that the linear addition product 13a and the cyclization products are not formed via a common intermediate.
Unexpected reaction of 4‐(2,4,6‐triphenylpyridinio)phenolate with urea in aqueous solution — structure of 1‐(4‐hydroxyphenyl)‐2,4,6‐triphenylpyridinium cyanate
Authors: Milart Piotr , Mucha Dariusz , Stadnicka Katarzyna 
Published: July 2007

AbstractDuring crystallization of the pyridinium N‐phenolate dye 1 from a saturated aqueous solution of urea, 1‐(4‐hydroxyphenyl)‐2,4,6‐triphenylpyridinium cyanate (4) is formed unexpectedly as verified by IR, 1H‐NMR and X‐ray structural analysis. Such a course of reaction can be explained by the strong nucleophilic character of the betaine dye 1. The anion of 4, [NCO]−, is disordered between two positions; one of them can be assigned to an isocyanate and the other to a cyanate group. The nitrogen atom of the anion is involved in an intermolecular, nearly linear hydrogen bond with the hydroxy group of the cation whereas its oxygen atom is pointing towards the pyridinium ring of an adjacent pyridinium cation.
3,4‐bis(O‐tert‐butyldimethylsilyl)‐6‐O‐tosyl‐D‐glucal: A probe for the mechanism of the iodine(III)‐promoted allylic oxidation of glycals
Authors: Kirschning Andreas 
Published: July 2007

AbstractThe reaction of 3,4‐bis(O‐tert‐butyldimethylsilyl)‐6‐O‐tosyl‐D‐glucal 4 with the Koser reagent [PhI(OH)OTs] unexpectedly afforded tetrahydrofurfural 6 as well as 2,3‐anhydropyranose 7 as major products. This unprecedented, stereoselective transformation helps to gain further insight into the mechanism of the well‐documented hypervalent iodine‐promoted allylic oxidation of cyclic enol ethers. A novel chemoenzymatic method for the preparation of glucal 4 in high yield is presented.
Glycolipids from sponges, III. Glycosyl ceramides from the marine sponge Agelas conifera
Authors: Costantino Valeria , Fattorusso Ernesto , Mangoni Alfonso 
Published: July 2007

AbstractThe glycosphingolipid (GSL) composition of the marine sponge Agelas conifera was investigated. In addition to three GSLs previous isolated from Agelas clathrodes (2a‐4a), the novel α‐glycosylceramide 1a was isolated as a major component of the GSL mixture, and its structure was elucidated by extensive NMR studies and by chemical analysis.