bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthese der Phoracantholide K, O und M
Authors: Gerlach Hans , Künzler Peter 
Published: December 2004

Synthesis of Phoracantholide K, O and MTwo 14membered ring lactones 3 and 4 and a 12membered ring lactone 5 isolated from the metasternal secretion of the eucalypt longicorn Phoracantha synonyma have been synthesized as racemic mixtures by the following method. Reaction of the dilithium derivative of 5‐hexynoic acid (6) with threo‐8‐bromo‐2,4‐isopropylidenedioxyoctane (7), followed by removal of the protecting group and esterification with diazomethane gave methyl‐threo‐11, 13‐dihydroxy‐5‐tetradecy‐noate (8) (s. Scheme 2). Partial hydrogenation of the triple bond in 8 with Lindlar Pd‐catalyst, followed by saponification lead to (threo, Z)‐11, 13‐dihydroxy‐5‐tetra‐decenoic acid (10). The dihydroxy acid 10 was converted into the S‐(2‐pyridyl) thioate and cyclized in diluted benzene solution under the influence of silver ions to yield the corresponding 12‐ and 14‐membered lactones in approximately equal amounts. Isomerization of the mixture with p‐toluenesulfonic acid in methylene chloride yielded the 14‐membered lactone (cis‐11, 13–5Z)‐11‐hydroxy‐5‐tetradecen‐13‐olide almost exclusively. It proved to be identical in its properties with natural phoracantholide K (3). With 5‐hexynoic acid and 7‐tetrahydropyranyloxy‐octyl bromide or 5‐tetrahydropyranyloxy‐hexyl bromide as starting materials (±)‐phoracantholide O (4) and M (5) have been synthesized in an analogous manner.
Beiträge zur Kenntnis des chromophoren Systems der Corrine. X. Über die Reaktion von Derivaten des Cobyrinsäure‐heptamethylesters mit unterchloriger Säure
Authors: Sauer Ernst Michael , Laas Harald , Inhoffen Hans Herloff 
Published: December 2004

Contributions to the Knowledge of the Corrin Chromophore, X. Reaction of Derivatives of Cobyrinic Acid Heptamethyl Ester with Hypochlorous Acid(Cobalt)‐dicyano‐, chloro‐cyano‐, and dichloro‐cobyrinic acid heptamethylesters (1, 2 and 3), respectively, as well as their 10‐chloro derivatives 4, 5 and 6 react with hypochlorous acid. A report on the structure and some properties of the reaction products 8, 9 and 10 is given.
Transition metal complexes with bidentate ligand 2, 11‐Bis (diphenylphosphinomethyl)benzo[c]phenanthrene (1). X. Preparation and spectroscopic properties of cis‐[PtCl2 (1)] trans‐ and cis‐[PtH (PPh3) (1)] [BF4] and crystal and molecular structure of cis‐[PtCl2 (1)] · CHCl3
Authors: Bracher Gustav , Grove David M. , Venanzi Luigi M. , Bachechi Fiorella , Mura Pasquale , Zambonelli Luigi 
Published: December 2004

AbstractIt is shown that ligand 1, designed to span trans‐positions, under appropriate conditions also gives cis‐mononuclear complexes of platinum (II). The structure of cis‐[PtCl2 (1)] (2) has been determined by single‐crystal X‐ray diffraction. The major distortion from square planar coordination is the P‐Pt‐P angle of 104.8°. Values of valence angles within the bidentate ligand indicate that this part of the molecule is very strained. Two phenyl groups, one on each phosphorus, lie almost parallel to each other separated by ca. 3.2–3.3 Å. The 1H‐NMR. data for this compound show that the π‐phenyl interactions observed in the solid state occur also in solution. The preparation and NMR.‐spectroscopic properties of trans‐ and cis‐[PtH(PPh3) (1)] [BF4] are reported.
Synthesis of Verrucarin A and 3α‐Hydroxyverrucarin A from Verrucarol and Diacetoxyscripenol (Anguidine). 39th Communication on Verrucarins and Roridins
Authors: Mohr Peter , Tori Motoo , Grossen Peter , Herold Peter , Tamm Christoph 
Published: December 2004

AbstractThe title compounds have been synthesized starting from verrucarol and diacetoxyscripenol (anguidine), (E, Z)‐muconic half ester and a derivative of verrucarinic acid. The latter has been prepared in optically active form from dimethyl 3‐methylglutarate.
Photoelectrochemistry with Colloidal Semiconductors; Laser Studies of Halide Oxidation in Colloidal Dispersions of TiO2 and α‐Fe2O3
Authors: Moser Jacques , Grätzel Michael 
Published: December 2004

Aqueous sols of TiO2 (anatase, particle radius 25 Å) were excited with (347.1 nm)‐laser light and the reaction of valence‐band holes with halide ions (X = I−, Br−, Cl−) was investigated. Hole transfer takes place within the duration of the (10 ns)‐laser pulse and results in the formation of anion radicals according to the sequence:magnified imageThe quantum yield of X increases in the order Cl < Br < I, attaining 0.8 for I at pH 1. It is affected by pH, halide concentration and the presence of a protective agent for the sol.RuO2 deposited onto TiO2 enhances markedly Cl and Br ‐formation, but has no effect on the yield of I.Laser‐photolysis investigation of halide oxidation were also carried out with colloidal Fe2O3 (particle radius 600 Å). For I2−formation, the quantum yield exceeds 0.9 indicating almost quantitative hole scavenging by iodide.
Directional Preferences of Ether O‐Atoms Towards Alkali and Alkaline Earth Cations
Authors: Chakrabarti Pinakpani , Dunitz Jack D. 
Published: December 2004

AbstractAn analysis of the environments of alkali and alkaline earth cations complexed to ethers has been made with the Cambridge Structural Database. The cations invariably lie close to the bisecting plane through the O‐atoms. The larger cations show an apparent preference to approach the ether group along a tetrahedral lone pair direction, whereas Li+ cations tend to be found along the COC bisector, i.e., along the trigonal lone pair direction. These observations are discussed in relation to recent theoretical and experimental findings.
Über die Enantiomerentrennung durch Verteilung zwischen flüssigen Phasen. 4. Mitteilung. Enantioselektivität der diastereoisomeren Weinsäure‐dimenthylester gegenüber α‐Aminoalkohol‐Salzen
Authors: Prelog Vladimir , Dumić Miljenko 
Published: December 2004

Separation of Enantiomers by Partition between Liquid Phases. Enantioselectivity of Diastereoisomeric Dimenthyl Tartarates towards α‐Aminoalcohol SaltsThe enantioselectivity of the easily obtainable diastereoisomeric dimenthyl tartarates I and II towards the salts of a series of α‐aminoalcohols 1‐10 was investigated by partition between aqueous and lipophilic phase. The measured enantiomer distribution constants Q (=KA/KB) confirm the previously observed configurational relationships between the lipophilic tartarates and the preferentially extracted enantiomer of the hydrophilic ammonium slat. However, the (R,R)‐ester I is appreciably more selective than its (S,S)‐diastereoisomer II or other previously investigated esters. The tartarates I‐III transport norephedrin salts through bulk lipophilic membranes with enantioselectivity comparable to that observed in partition experiments. The most enantioselective ester I can be used as an efficient mobile phase for preparative separation of norephedrine enantiomers by flash partition chromatography.
An Fe57Mössbauer Study of Selected Binary and Ternary Vanadium Sulfides
Authors: Bensch Wolfgang , Schlögl Robert , Amberger Eberhard 
Published: December 2004

AbstractMössbauer data recorded at room temperature and 78 K for several binary and two new ternary vanadium sulfides are presented. The results are discussed in comparison with the structures and magnetic susceptibility measurements. A change in the spin state of the Fe‐atoms from the Fe2+ high‐spin state to the low‐spin state is observed in the binary vanadium sulfides. This change is due to a shortening of the crystallographic c‐axis which is nearly parallel to short metal‐metal distances. In one ternary thallium vanadium sulfide the Fe is in the unusual trivalent low‐spin state at room temperature.
Syntheses of Cyclopropyl Silyl Ketones
Authors: Scheller Markus E. , Frei Bruno 
Published: December 2004

AbstractThe synthesis of the cyclopropyl silyl ketones 1–4 is described. The trimethylsilyl ketone 1 was prepared from geraniol ((E)‐5) in ca. 10% overall yield by cyclopropanation leading to 6, CrO3 oxidation to the aldehyde 8, reaction of the latter with trimethylsilyl anion to 14A+B, and CrO3 oxidation to 1. Also for the (t‐butyl)dimethylsilyl ketones 2–4, an efficient four‐step synthesis with overall yields of 48%, 85%, and 13%, respectively, was elaborated, starting from the allylic alcohols (E)‐5, and 23. The method of preparation involves as the key step a Wittig rearrangement of the silylallyl ethers ((E/Z)‐20, 24) to the silyl alcohols ((E/Z)‐21, 25), subsequent cyclopropanation (19A + B, 22A + B, 26), and oxidation to the cyclopropyl silyl ketones 2–4.
Metal complexes with macrocyclic ligands. Part XXII. Synthesis two of bis‐tetraaza‐macrocycles and study of the structures, electrochemistry, VIS and EPR spectra of their binuclear Cu2+ and Ni2+ complexes
Authors: Schneider Renè , Riesen Andreas , Kaden Thomas A. 
Published: December 2004

AbstractThe two bis‐macrocycles 4 and 5 in which the tetraaza units are separated by a chain of different length, have been synthesized using 1,4,7‐tritosyl‐1,4,7,11‐tetraazacyclotetradecane as starting compound and bifunctional alkylating agents. The bis‐macrocycles give binuclear complexes with Ni2+ and Cu2+, the properties of which have been studied to obtain information about the interaction of the two subunits as a function of the distance. The VIS spectra of the Ni2+ and Cu2+ complexes indicate that both metal ions are in a square‐planar geometry as expected from the results of the analogous complexes with 1,4,7,11‐tetraazacyclotetradecane 7. Cyclic voltammetry and differential pulse polarography of the binuclear Ni2+complexes in CH3CN show a single two‐electron step for ligand 5, whereas two distinct one‐electron redox processes can be observed for ligand 4, indicating that the two metal ions interact with each other when the chain length is shorter. Similarly, the EPR studies of frozen solutions of the binuclear Cu2+ complexes clearly show that a magnetic dipolar interaction between the two paramagnetic centers exists, and that the strength of it depends upon the length of the bridge. Finally, from the X‐ray structures of the binuclear Ni2+ complexes with 4 and 5, it is seen that the two rings are kept apart as far as possible, the distances between the two metal ions determined in the solid correlate well with the observations in solution.
C45‐ und C50‐Carotinoide. 3. Mitteilung. Synthese von (S)‐Trisanhydrobacterioruberin
Authors: Wolf Jean‐Pierre , Pfander Hanspeter 
Published: December 2004

C45‐and C50‐Carotenoids: Synthesis of (S)‐TrisanhydrobacterioruberinThe Synthesis of (S)‐trisanhydrobacterioruberin ((S)‐1) is reported.
1H‐ and 13C‐NMR Investigation of Nonafulvenes
Authors: Otter Albin , Sabbioni Gabriele , Neuenschwander Markus , Kellerhals Hans Peter 
Published: December 2004

Abstract1H‐ and 13C‐NMR spectra of a series of nonafulvenes 1 have been investigated. Most nonafulvenes are olefinic molecules with alternating bond lengths, their nine‐membered ring deviating strongly from planarity. The 10‐monosubstituted nonafulvenes contain 2 sterically different ring segments with a nearly planar (E)‐diene system consisting of C(7), C(8), C(9), C(10), and R. Substituents R are influencing C(9) > C(7) > C(5). In symmetrically substituted nonafulvenes a fast process equilibrating olefinic conformers is operating so that pairs of ring protons and ring C‐atoms are equivalent and only average substituent effects are observed for C(9) > C(7,2). 1H‐ and 13C‐NMR chemical shifts are not significantly influenced by changes of solvent or temperature. On the other hand, new 13C‐ and 1H‐NMR experiments completing previous investigations by Hafner and Tappe confirm that NMR spectra of 10,10‐bis (dialkylamino)nonafulvenes are strongly dependent on solvent polarity and temperature. At ambient temperature and in unpolar solvents, nonplanar conformers are predominant, their spectral data fitting into the series of other nonafulvenes. At low temperature and/or in polar solvents, dipolar conformers are favoured which are characterised by charge separation and a planarised (but not necessarily completely planar) nine‐membered ring with negative excess charge. The spectroscopic behaviour of nonafulvenes is reasonably explained by a qualitative scheme (Fig. 7) which is based on a model proposed by Boche for nonafulvenolates.
Conformation‐Odor Relationships in Norlabdane Oxides
Authors: Ohloff Günther , Vial Christian , Demole Edouard , Enggist Paul , Giersch Wolfgang , Jégou Elise , Caruso Andrew J. , Polonsky Judith , Lederer Edgar 
Published: December 2004

AbstractConformational factors have been found responsible for the dramatic change in odor between (−)‐deoxyambreinolide (12) and its (+)‐epi derivative 13. The presumably molecular event during the receptor interaction has been simulated by the diastereoisomeric 11‐methyl‐ambrox derivatives 3 and 5 as model compounds.
Additionsreaktion von 1,3‐Thiazol‐5(4H)‐thionen und inaminen; Bildung von Thioamiden und Thioketonen
Authors: Jenny Christjohannes , Heimgartner Heinz 
Published: December 2004

Addition Reaction of 1,3‐Thiazole‐5(4H)‐thiones and Ynamines; Formation of Thioamides and ThioketonesYnamines and 1,3‐thiazole‐5(4H)‐thiones of type 1 undergo an addition reaction on heating in toluene yielding mainly α,β‐unsaturated 2‐(4,5‐dihydro‐1,3‐thiazol‐5‐yliden)thioamides of type 7 (Scheme 2 and Table). In some cases, 1‐diethylamino‐1‐(4,5‐dihydro‐1,3‐thiazol‐5‐yliden)‐2‐alkanethiones 8 have been isolated as minor products. In analogy to other reactions of ynamines with CO and CS bonds, a [2 + 2] cycloaddition to thiete intermediates, followed by an electrocyclic ring opening is suggested as reaction mechanism.
Synthesis of (E)‐1‐Propenyl Ketones from Carboxylic Esters and Carboxamides by Use of Mixed Organolithium‐Magnesium Reagents. Synthesis of α‐Damascone, β‐Damascone, and β‐Damascenone
Authors: Fehr Charles , Galindo José 
Published: December 2004

AbstractThe novel reagents formed by combination of allylmagnesium chloride and a strong non‐nucleophilic lithium base (LiNR2) convert non‐ or slowly enolizable carboxylic esters or carboxamides into 2‐propenyl ketones which are protected from further reaction by their in situ conversion into enolates. This modified Grignard reaction is applied to efficient syntheses of α‐damascone, β‐damascone, β‐damascenone, and various other (E)‐1‐propenyl ketones.
Drug‐induced modifications of the immune response part 94‐(Arylamino)‐2,5‐dihydro‐2‐oxo‐N‐(trans‐2‐phenylcycolopropyl)furan‐3‐carboxamides as Novel Antiallergic Compounds
Authors: Georgiev Vassil St. , Mack Robert A. , Walter David J. , Radov Lesley A. , Baer Jane E. 
Published: December 2004

AbstractThe synthesis and antiallergic activity of a series of 4‐(arylamino)‐2,5‐dihydro‐2‐oxo‐N‐(trans‐2‐phenyl‐cyclopropyl)furan‐3‐carboxamides 10 are described. Treatment of N‐substituted 2‐amino‐4,5‐dihydro‐4‐oxofuran‐3‐carboxylic acids 9 with chlorooxobis(2‐oxo‐1,3‐oxazolidin‐3‐yl)phosphorus (2) and an appropriate aromatic amine in the presence of Et3N, resulted in a novel 3(2H)‐furanone‐→2(5H)‐furanone rearrangement that led to the facile preparation of the new amides 10. The latter exerted a potent antiallergic activity when tested in the dermal vascular permeability and active anaphylaxis assays in rats. The most active compound 10b inhibited the action of serotonin, histamine, and bradykinin by 94, 92, and 100%, respectively, when administered intraperitoneally to rats at doses of 100 mg/kg. The present series of 10 represents a novel class of antiallergic agents.
On Negative Birefringence in Water‐in‐Oil Microemulsions
Authors: Hilfiker Rolf , Eicke Hans‐Friedrich , Hammerich Holger 
Published: December 2004

AbstractThe occurrence of a negative birefringence in water‐in‐oil (W/O) microemulsions has been substantiated and analyzed. The analysis is based on the well‐established aqueous nanodroplet model of W/O microemulsions. In the particularly investigated water/sodium bis(2‐ethylhexyl)sulfosuccinate (AOT)/aliphatic oil systems, the AOT monolayer exhibits a negative induced intrinsic birefringence, which is brought about by the pronounced polarizability of the alkyl moiety of the AOT molecule approximately perpendicular to the direction of its permanent dipolement.
Two New Antifungal Naphthoxirene Derivatives and their Glucosides from Sesamum angolense WELW
Authors: Potterat Olivier , Stoeckli‐Evans Helen , Msonthi Jerome D. , Hostettmann Kurt 
Published: December 2004

AbstractTwo novel naphthoxirene derivatives 1 and 2 their glucosides 3 and 4 have been isolated from the root bark of Sesamum angolense Welw. (Pedaliaceae) by preparative liquid chromatography. The structure of 1 was established by X‐ray diffraction analysis. The identities of the other naphthcxirenes were deduced by spectroscopic (IR, UV, 1H‐NMR, 13C‐NMR, EI‐MS, DCI‐MS) and chemical methods (oxidation, acid and enzymatic hydrolysis). Compounds 1–3 exhibited antifungal activity. Naphthoxirene 1 was, in addition, cytotoxic to human colon carcinoma cells.
N6‐(Carbamoylmethyl)‐2′‐deoxyadenosine, a rare DNA Constituent: Phosphoramidite Synthesis and Properties of Palindromic Dodecanucleotides
Authors: Seela Frank , Herdering Wilhelm , Kehne Andreas 
Published: December 2004

AbstractN6‐(Carbamoylmethyl)‐2′‐deoxyadenosine (1), a modified nucleoside occurring in bacteriophage Mu, was synthesized by two different routes. Glycinamide was introdued by nucleophilic displacement of(2,4,6,‐triisopro‐pylphenyl)sulfonyloxy or ethylsulfinyl groups at C(6) of the purine moiety. Compound 1 was converted into the protected phosphoramidite 6b and employed in solid‐phase synthesis of the self‐complementary oligonucleotides 7–14. Replacement of 2′‐deoxyadenosine by 1 led to a strong decrease of the Tm values of the oligomers d(A‐T)6 (7) and d(A‐T‐G‐A‐A‐G‐C‐T‐T‐C‐A‐T)(10), respectively. As the oligemer 10 contains the recognition site d(A‐A‐G‐C‐T‐T) of the endodeoxyribonuclease Hind III, it was subjected to sequence‐specific hydrolysis experiments. Replacement of the first or second Ad by 1 prevented enzymatic phosphodiester hydrolysis (results with 11 and 12). In contrast, slow hydrolysis was observed if the less bulky N6‐methyl‐2′‐deoxyadenosine replaced the second Ad residue (results with 14).
Synthesis of Chiral 12‐Phenyl(2H)dodecanoic Acids: Useful metabolic probes for the biosynthesis of 1‐alkenes from fatty acids
Authors: Görgen Günther , Boland Wilhelm , Preiss Ute , Simon Helmut 
Published: December 2004

AbstractThe synthesis of chiral 12‐phenyi(2H)dodecanoic acids as metabolic probes for the evaluation of the stereo‐chemical course of the biosynthesis of 1‐alkerses from fatty acids in plants and insects is described. The diastereoisomeric (2R, 3R)‐ or (2S, 3S)‐12‐phenyl(2,3−2H2)dodecanoic acids 11 are obtained in high chemical and optical yield (>97% e.e.) from the readily available (E)‐12‐phenyl(2,3‐2H2)dodec‐2‐enoic acid (10) or (E)‐12‐phenyldodec‐2‐enoic acid (10a) by microbial reduction with wet packed cells of Clostridium tyrobutyricum in either 2H2O or H2O buffer. (2R)‐ and (2S)‐12‐phenyl(2−2H)dodecanoic acids 9 (>97% e.e.) are accessible from the allylic alcohol 6 via Sharpless epoxidation with (+)‐L‐ or (−)‐D‐diethyl tartrate, Synthetic routes to the (E)‐ and (Z)‐11‐phenyl(1−2H) undec‐1‐enes 16 and 16a as reference compounds are also included.
Verschiedenartige Addukte von Ketonen, Diazocyaniden sowie Nitrosobenzol an (Methylidenamino)phosphene
Authors: Ried Walter , Fulde Maria , Bats Jan W. 
Published: December 2004

AbstractVarious Adducts from Ketones, Diazocyanides, and Nitrosobenzene with (Methylidenamino)phosphines(Methylidenamino)phosphine 1a reacts with activated ketones to 2,7‐dioxa‐5‐aza‐1λ5‐phosphabicyclo‐[3.2.0]heptanes 2a, b and with nitrosobenzene to l, 3,5,2λ5‐oxadiazaphosphole 3a. The reaction of 1b with nitrosobenzene and diethyl mesoxalate yields 2,7‐dioxa‐3,5‐diaza‐1λ5‐phosphabicyclo[3.2.0]heptane 4. With the cyano group of diazocyanides, 1a reacts to the adducts 5a–d. The structure of 5a is proven by an X‐ray diffraction analysis.
Energy‐Minimized Structures and Calculated and Experimental Isomer distributions in the hexaamine‐cobalt(III) system [Co(L)2]3+ with the chiral facially‐coordinating triamine (l = butane‐1,2,4‐triamine)
Authors: Comba Peter , Maeder Marcel , Zipper Luc 
Published: December 2004

AbstractButane‐ 1,2,4‐triamine (trab) is the smallest tridentate aliphatic unsubstituted chiral triamine. With optically pure trab, there are three, with racemic trab five isomers of [Co(trab)2]3+, One of the five isomers is centrosymmetrical, the others are chiral. For one of the isomers, there are four possible conformations (all combinations of chair and skew boat conformations for the chelate six ring of each ligand), for the others there exist only three independent conformers. All sixteen independent structures have been calculated by strain‐energy minimization. The calculated isomer distribution, based on total strain energies corrected with statistical entropy contributions (21%:16%:16%:4%:43%, and 40%:30%:30%, for racemic and optically pure trab, respectively) are in excellent agreement with the experimental data based on HPLC and 13C‐NMR analyses of equilibrium solutions of the hexaamine‐Co(III) compounds prepared by oxygenation of aqueous solutions in presence of activated charcoal. The results are also briefly discussed in relation to possible stereoselectivity upon complexation of optically pure trab and a racemic chiral ligand to a transition‐metal center.
An Unexpected Asymmetric Reduction of 4‐(1‐Nitro‐2‐oxocyclododecyl)butan‐2‐one. Determination of the absolute configuration of (‒)‐15‐hexadecanolide
Authors: Stanchev Stephan , Hesse Manfred 
Published: December 2004

AbstractReduction of the carbonyl group in the side chain of 4‐(1‐nitro‐2‐oxocyclododecyl)butan‐2‐one (3) with organoboron complexes are influenced by the chiral center, in 4‐position with respect to the carbonyl C‐atom, to which the NO2 group is attached, a rare type for an asymmetric reduction. Independent of the (R)‐ or (S)‐configuration of the Alpine‐Hydride, (+)‐3 is reduced only to the (15S)‐nitrolactone (+)‐5 and, after subsequent transformations, to (+)‐(‐S)‐15‐hexadecanolide ((+)‐1), enantiomer of the naturally occurring (−)‐1.
Synthesis of Polyaza Macrocyclic Ligands Incorporating Pyridine Units
Authors: Hosseini Mir Wais , Comarmond Jacques , Lehn Jean‐Marie 
Published: December 2004

AbstractThe synthesis of nine macrocyclic polyamines 2‐10 containing pyridine units is described. These compounds are 22‐ (9), 24‐ (2‐4,6,8,10), or 26‐ (5, 7) membered hexaaza (2,3,9,10) or octaaza (4–7) macrocycles in which one to four pyridine units are incorporated. Compounds 3,4,9, and 10 are homoditopic ligands, whereas 2 and 5 are heteroditopic and 6−8 multitopic receptors. Compounds 2‐10 are potential ligands for metal cations as well as, in their protonated forms, for anions. Protonated macrocycles 2−10 are also potential catalysts for the hydrolysis of nucleotides and polyphosphates.
Bretonin A and Isobretonin A, Unique Glycerol Derivatives Isolated from a Demosponge of Brittany Waters
Authors: Guella Graziano , Mancini Ines , Pietra Francesco 
Published: December 2004

AbstractIt is shown that an unidentified marine demosponge of Brittany contains two unique lipids consisting of glycerol etherified by a C12 trienic linear alcohol and esterified by 4‐hydroxybenzoic acid. The latter is attached to the secondary position of glycerol in bretonin A (= 3‐[((4E, 6E, 8E)‐dodeca‐4,6,8‐trienyl)oxy]‐2‐(4‐hydroxy‐benzoyl)propan‐1‐ol; 1a), and to the other primary position of glycerol in isobretonin A ( = (+)‐3‐[((4E, 6E, 8E)‐dodeca‐4,6,8‐trienyl)oxy]‐1‐(4‐hydroxybenzoyl)propan‐2‐ol; (+)‐2). The structures are based on NMR and MS data, including the ones of the acetylation product (−)‐1b of 1a.