bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Inversion of the Amino Group in Vinylamine, a Flexible Model Treatment
Authors: Meyer Rolf 
Published: December 2004

AbstractFlexible model results for the NH2 inversion in vinylamine are compared with microwave data published by Lovas et al. [3]. The information available on the spacing of inversion levels is found to be sufficient to rule out a planar equilibrium structure. Shifts of rotational constants upon excitation of the inversion are calculated for two predicted paths of motion derived from PRDDO geometry optimization results obtained by MiiIler & Brown [2]. Partial geometry optimization yields a path inconsistent with experiment but the path obtained from complete optimization produces shifts in excellent agreement with the observed shifts. A potential energy function compatible with experimental data on spacing of inversion levels is calculated from the observed inertia defects. The inversion angle at equilibrium is slightly smaller than the angle predicted from PRDDO calculations, and the barrier to inversion, ΔV = 1.08 ± 0.07 kcal/mol, is approximately half the PRDDO value.
Identification de stérols à chaînes latérales courtes dans l′éponge Damiriana hawaiiana
Authors: Delseth Claude , Carlson R. M. K. , Djerassi Carl , Erdman Timothy R. , Scheuer Paul J. 
Published: December 2004

Identification of short side chain sterols in the sponge Damiriana hawaiianaThe steroidal composition of the sponge Damiriana hawaiiana is examined. Twenty‐seven components are identified. In addition to the C26‐C29, Δ5‐mono and diunsaturated sterols, the sponge contains sterols without side‐chain: androsta‐5, 16‐dien‐3β‐ol(1), androst‐5‐en‐3β‐ol(2); sterols with a non‐functionalized side‐chain consisting of two, three, four, five and six carbon atoms: pregna‐5, 20‐dien‐3β‐ol(5), pregn‐5‐en‐3β‐ol(6), 23, 24‐bisnor‐chola‐5, 20‐dien‐3β‐ol(7), 23, 24‐bisnor‐chol‐5‐en‐3β‐ol(8), 24‐nor‐chol‐5‐en‐3β‐ol(10), chol‐5‐en‐3β‐ol(11), 26, 27‐bisnor‐cholest‐5‐en‐3β‐ol(12), and sterols possessing a short oxygenated side‐chain such as 3β‐hydroxy‐androst‐5‐en‐17‐one(3), androst‐5‐en‐3β, 17β‐diol(4) and 3β‐hydroxy‐26, 27‐bisnor‐22‐trans‐cholesta‐5, 22‐dien‐24‐one(14). The probable biological or dietary origin rather than artifact production of these hitherto undescribed components from marine sources is supported by their relatively high concentration and their relative proportions, both very different from those expected for autoxidation.
Zum photochemischen Verhalten von Sydnonen und 1,3,4‐Oxadiazolin‐2‐onen. 56. Mitteilung über Photoreaktionen
Authors: Märky Michael , Meier Hansruedi , Wunderli Alfred , Heimgartner Heinz , Schmid Hans , Hansen Hans‐Jürgen 
Published: December 2004

On the Photochemistry of Sydnones and 1,2,3,4‐Oxadiazolin‐2‐onesThe photochemical behaviour of several 3,4‐disubstituted sydnones (cf. Scheme 5) dioxane solution was investigated. The pure sydnones give, as was already reported [2–6], 2,4,5‐trisubstituted 1,2,3‐triazoles 2 (cf. Scheme 1) in 25–30% yield. In the presence of dipolarophiles (cf. Scheme 1) pyrazole derivatives 3 or 4 are formed which can be taken as a proof for the formation of nitril‐imines 5 as primary products in sydnone photochemistry. Since irradiation of 2‐[15N]‐3, 4‐diphenyl‐sydnone (2‐[15N]‐15) in dioxane leads to the formation of 1,3‐[15N]‐2,4,5‐triphenyl‐1,2,3‐triazole (1,3‐[15N]22; cf. Scheme 10), nitril‐imine formation must be induced by the creation of a bond between N(2) und C(4) in the excited sydnones (cf. Scheme 22). The irradiation of sydnones in dioxane solution in the presence of carboxylic acids yields N′‐acylhydrazides in 50–70% (cf. Scheme 14), the formation of which can be explained by addition of the acids to the nitril‐imines and rearrangement of the primarily formed anhydride monohydrazones (Scheme 15). By analogy, the formation of 1‐benzoyl‐2‐(t‐butyl)‐4‐phenyl‐1,2‐diazetidin‐3‐one (14; Scheme 4) during the photolysis of 3‐(t‐butyl)‐4‐phenylsydnone (12) in benzene solution (cf. [5b]) may also be explained: Sydnone 12 undergoes two different photoreactions leading by loss of carbon dioxide to the corresponding nitril‐imine 5 (R=t‐C4H9, R′ C6H5) and by loss of isobutylene to a 1,2,3‐oxadiazolin‐5‐one of type 48 or 49 which isomerizes to yield diazophenylacetic acid (51; cf. Scheme 17). Reaction of both products (5 and 51) results in the formation of the N′‐acylhydrazide 52 (Scheme 18) which may cyclize after loss of nitrogen to yield the diazetidinone 14 in a carbene type reaction. The triazoles 2 are formed photochemically from the corresponding 1,2‐bisazo‐ethylenes 64 (Scheme 26) which arise from a direct ‘head‐to‐head’ dimerization of the nitril‐imines 5. This type of reaction seems to be common to all nitrilium betaines (Schema 30). The photolysis of the 2,4‐disubstituted 1,3,4‐oxadiazolines 76 does not lead to nitril‐imines 5 (cf. [11]). On the contrary, loss of carbon monoxide induces the formation of azoketones 77 (cf Scheme 31), which may be photo‐reduced to yield hydrazides or may undergo cleavage of the N, acyl bond to form derivatives of1,2‐diketones (cf. Scheme 32).
Total Synthesis of Indole and Dihydroindole Alkaloids. XV. Further Chemistry of Vindoline
Authors: Kutney James P. , Bunzli‐Trepp Ursula , Honda Toshio , Katsube Junki , Worth Brian R. 
Published: December 2004

AbstractThe general reactivity of various sites in the vindoline series has been investigated. The facility of electrophilic substitution at C(15) and the effect of steric crowding on reactions at C(4) are discussed. At the basic nitrogen sites, oxidations with mercuric acetate and potassium permanganate are also discussed.
Inductive, Hyperconjugative and Frangomeric Effects in the Solvolysis of 1‐Substituted 3‐Bromoadamantanes. Polar effects IV
Authors: Fischer Walter , Grob Cyril A. 
Published: December 2004

AbstractThree kinds of polar substitutent effects are observable in the solvolyses of 1‐R‐substituted 3‐bromoadamantanes (VI). This follows from the relationship between products, rate constants k in 80% ethanol, and the inductive substituent constants σ of the substituent R. Alkyl groups and electron‐attracting substituents at C (1) control the rate by their inductive effects alone, since logk correlates closely with σ. However, rates are higher than predicted on the basis of the respective σ values when conjugating (+ M)‐substituents or electrofugal groups are attached to C(1). These exalted substituent effects are attributed to CC‐hyperconjugative relay of positive charge from the cationic center at C(3) to the substituent at C(1). When the substituent is a strong electron donor (e.g. O− and S−), accelerated substitution gives way to heterolytic fragmentation, rates and products then being controlled by the frangomeric effect.
Nucleoside und Nucleotide. Teil 11. Phosphorylierung von 1‐(2′‐Desoxy‐β‐D‐ribofuranosyl)‐2(1H)‐pyridon und dessen Verhalten bei der Synthese von Dinucleotiden
Authors: Waldmeier Felix , Tamm Christoph 
Published: December 2004

Nucleosides and Nucleotides, Part 11. Phosphorylation of 1‐(2′‐Desoxy‐β‐D‐ribofuranosyl)‐2(1H)‐pyridon and its Behaviour in the Synthesis of DinucleotidesThe behaviour of the unnatural nucleoside 1‐(2′‐deoxy‐β‐D‐ribofuranosyl)‐2(1H)‐pyridon (Πd, 1) in the synthesis of dinucleotides with purine deoxynucleotides was studied. The optimized preparation of the protected dinucleoside phosphates (MeOTr) Πd pG (5) and (MeOTr) Πd pA (7) using the diester method of Khorana with DCC as condensing agent is described. The removal of the N‐acyl‐ and p‐methoxytrityl groups was effected by successive treatment with conc. ammonia solution and acetic acid/water 1:1 at 23° yielding the free dinucleoside phosphates ΠdpGd (9) and ΠdpAd (11). In a similar way, starting from (CNEt) pΠd(15), the dinucleotides pΠdpG (16), pΠdpGd (18), pΠdpA (17) and pΠdpAd (19) were synthesized.The nucleotide 1‐(5′‐O‐Phosphoryl‐2′‐deoxy‐β‐D‐ribofuranosyl)‐2(1H)‐pyridon (pΠd, 3) was prepared in excellent yield by selective phosphorylation of Πd (1) using phosphorylchloride in triethyl phosphate at −40°. Deoxyadenosine was phosphorylated in the same way.The compounds were characterized by UV. spectroscopy, chromatography and enzymatic degradation.
Eine einfache Veresterungsmethode im Eintopf‐Verfahren
Authors: Stadler Paul Albert 
Published: December 2004

A simple one‐pot method for esterificationA one‐pot procedure for esterifications of primary, secondary and tertiary alcohols and of phenols in high yield is described. Reaction of oxalylchloride with dimethylformamide in a suitable solvent affords dimethylformamide imidechloride; addition of an acid to the suspension of this reagent furnishes an activated carboxy‐group derivative, which is then transformed to an ester by addition of pyridine and an alcohol ro a phenol. Reaction temperatures needed for esterification are low, usually 0° to room temperature, reaction times are short.
Über die Temperaturabhängigkeit der 13C‐NMR.‐Spektren von [5–6‐η‐(1Z, 5E)‐Cyclooctadien]tetracarbonyleisen und (1Z, 5E)‐Cyclooctadien
Authors: Von Büren Martin , Bischofberger Pius , Hansen Hans‐Jürgen 
Published: December 2004

On the Temperature Dependence of the 13C‐NMR. Spectra of [5‐6‐η‐(1Z,5E)‐Cyclooctadien] and of (lZ, 5E)‐CyclooctadieneThe activation parameters of the conformational ring inversion process (simultaneous rotation around the C(3), C(4) and C(7), C(8) bonds; cf. Scheme 1) of the title compounds (1 and 2, respectively) have been determined between 275 L and 155 K by a complete line shape analysis of the temperature dependent proton noise‐modulated decoupled 13C‐NMR. spectra of 1 and 2. The temperature dependence of the rates (k(1) and k(2), respectively) of the inversion process can be described by the following equations (no influence of the solvents was observed; Ea in J/mol):

. Further data are given in Tables 1 and 2.The carbonyl groups of the complex 1 show at 180 K, where the ring inversion process is frozen out, a single line at 211 ppm, i. e. the coalescence temperature of the carbonyl groups must be < 180 K.
Hydroformylation of 1, 1, 1‐d3‐2‐butene. Isotope Effect on the Product Composition
Authors: Consiglio Giambattista , von Bézard Denis A. , Morandini Franco , Pino Piero 
Published: December 2004

AbstractIn the hydroformylation of 1,1,1‐trideuterio‐2‐butene with Rh4 (CO)12 the deuterated pentanals formed contain 75% of 5,5,5‐trideuterio‐pentanal, the rest being substantially 2,2‐dideuterio‐pentanal. On the contrary, using Co2 (CO)8 as the catalyst precursor, position 1 and 4 are formylated to the same extent.
Tricyclo[4.2.2.22,5] dodecane and Tricyclo [4.2.2.12,5]undecane. Preliminary communication
Authors: Ernst Beat , Ganter Camille 
Published: December 2004

AbstractA synthesis of tricyclo [4.2.2.22,5]dodecane (19), a novel tricyclic C12H20 compound, is described. The key intermediate ketone 13 was prepared either from the C10‐photodimer 1 of cyclopentadienone or the C11‐cycloaddition products 11 and 12. 13 was also transformed to tricyclo [4.2.2.12,5]undecane (8).
Die Reaktion von 4,6‐Dinitroisophthalaldehyd und 4,6‐Dinitroisophthalonitril mit Pyridin
Authors: Adam Jean‐Marie , Hindermann Peter , Winkler Tammo 
Published: December 2004

The reaction of 4,6‐dinitroisophthalaldehyde and 4,6‐dinitroisophthalonitrile with pyridine4, 6‐Dinitroisophthalaldehyde (4) gives on reaction with pyridine 4,6‐diformyl‐3‐(1′‐pyridinio)‐1‐phenolate (5), whereas 4,6‐dinitroisophthalonitrile (7) gives under the same conditions one main product: 3‐(1′)‐pyridinio‐4, 6‐dicyano‐1‐phenolate (10) and two side products: 2‐(1′‐pyridinio)‐4, 6‐dicyano‐3‐nitro‐1‐phenolate (11) and 4, 6‐dicyano‐3‐nitro‐1‐phenol (12). The new structures were elucidated by 1H‐NMR. and 13C‐NMR. spectroscopy.
The Reaction of SnCl2 with the Complexes cis‐PtCl2 (phosphorus ligand)2 as studied by 31P and 195Pt NMR
Authors: Pregosin Paul S. , Sze Siu Ning 
Published: December 2004

AbstractThe reactions of SnCl2 with the complexes cis‐PtCl2P2, P=trialkyl and triaryl phosphines and phosphites, in CDCl3 and CD2Cl2 have been studied using 31P and 195Pt NMR. methods. For equimolar amounts of Sn and Pt, products of the type PtCl(SnCl3)P2 are formed with the complex geometry depending on the nature of P. For PPEt3 and P(OPh)3, further addition of SnCl2 produces trans‐Pt(SnCl3)2 complexes. The syntheses of trans‐PtCl(SnCl3) (PEt3)2 and trans‐Pt(SnCl3)2 (OPh3)2 are described.
Untersuchungen über Allylgruppenwanderungen in aliphatischen Carbenium‐Ionen
Authors: Dillenberger Zuva , Schmid Hans , Hansen Hans‐Jüren 
Published: December 2004

Investigations on the Migratory Aptitude of Allyl Groups in Aliphatic Carbenium‐IonsThe acetolysis (80°) of the 4‐bromobenzenesulfonates given in Scheme 6 were investigated in regard to determine type allyl/methyl migratory aptitudes in the secondary carbenium ion a (Scheme 24). In all cases olefins (about 80%) and acetates (about 20%) were formed which can be derived from the rearranged tertiary carbenium ions b (being formed by allyl group migration) and c (being formed by methyl group migration).Olefin A and acetate H, originated in carbenium ion a, occurred in the acetolysis mixture only in minor amounts (<2%). By acetolysis of [l4C]‐20, isolation of [14C]‐4,5‐dimethyl‐l, 3‐hexadiene ([14C]‐45), and degradation of this diene (Scheme 16) it could be shown (4 Scheme 15) that the ions b and c (Scheme 24, R1R4H) are not interconverted by a [1,2]‐hydride shift (extent < 1%). Since olefin D arises by proton loss from ion b as well as from ion c, [14C]‐4,5‐dimethyl‐l,4‐hexadiene ([14C]44 D, R1R4 H) was also degraded (cf. Scheme 15 and Scheme 17). It was found that [14C]‐44 contained 48% of the label in the methyl group at C(4) and 52% in the methyl groups at C(5), i.e. 48% of 44 is formed via the allyl migration path and 52% via the methyl migration path. In addition, acetolysis of d3‐20 and product analysis showed, that the d3‐ally1 moiety migrates as expected only in a [1,2]‐fashion. Product analysis of the acetolysis mixtures of erythro‐ and threo‐24 (cf. Scheme 19 and Tables 4 and 5) revealed that carbenium ion a must exist as an intimate ion pair (with the 4‐bromobenzenesulfonyloxy‐ion) which has lost its configuration at C(1) only partially. This is indicated by reversed ratios (1: 11 and 10: 1, resp.) in the formation of erythro‐ and threo‐2,3,4‐trimethyl‐l, 5‐hexadiene (erythro‐ and threo‐77) arising from ion b (Scheme 24, R1R3  H, R4 CH,). The acetolysis of 1,2,2,4‐tetramethyl‐4‐pentenyl4‐bromobenzenesulfonate (23) was not studied in detail, but the appearance of a seventh product in the olefin part cannot be explained by the genesis paths in Scheme 24. Thus, it may be concluded that in this case a third tertiary carbenium ion d3 (Scheme 21) is produced by cyclization of a3. Cyclizations of this type are known to occur in carbenium ions bearing β‐substituted allyl groups (see Scheme 22). The kinetic data of the acetolysis of all 4‐bromobenzenesulfonates (Table 6) are in accord with a rate determining ionization step leading to a since all activation enthalpies resp. entropies are within 25.5 L± 0.6 kcal/mol resp. −0.2 ± 1.7 e.u. The migratory aptitudes given in Table 7 show, that allyl groups migrate only slightly easier than methyl groups in ion a. This is in strong contrast to allyl substituted methylcyclohexadienyl cations (generated in the acid catalyzed dienone/phenol and dienol/benzene rearrange‐ment) which undergo exclusively [1,2]‐ally1 migrations (Schemes 3‐5).
α‐Hydroxymethylen‐verlängerte Aldehyde durch schonende Reduktion von Cyanhydrinen
Authors: Schlosser Manfred , Brich Zdenêk 
Published: December 2004

α‐Hydroxymethylene Elongated Aldehydes by Partial Reduction of CyanohydrinsAfter acetal‐protection of the hydroxy group, a number of cyanohydrins (derived from aldehydes or ketones) were reduced and hydrolysed to afford α‐hydroxyaldehydes in good yields. Other synthetically useful reactions of the intermediate α‐cyano and α‐formyl acetals have also been studied.
The Enantioselective Synthesis of 3‐Methoxy‐1, 3, 5 (10)‐estratrien‐11, 17‐dione by a Thermal Intramolecular Cycloaddition Reaction. Preliminary communication
Authors: Oppolzer Wolfgang , Bättig Kurt , Petrzilka Martin 
Published: December 2004

AbstractThe enantiomerically pure (+)‐3‐methoxy‐1, 3, 5 (10)‐estratrien‐11, 17‐dione 11 (with trans‐anti‐trans configuration) was synthesized in a highly stereocontrolled fashion from (±)‐t‐butyl 4‐methoxy‐1‐benzocyclobutene carboxylate (8) and the (+)‐carboxylic acid 6, obtained from 4 in two steps, followed by one crystallization of the (+)‐ephedrine salt. The key step 10→11 (Scheme 2) involves a thermal intramolecular cycloaddition reaction.
Stoffwechselprodukte von Mikroorganismen. 174. Mitteilung Eine neue Synthese des Ferrichroms; enantio‐Ferrichrom
Authors: Naegeli Hans‐Ulrich , Keller‐Schierlein Walter 
Published: December 2004

Metabolites of Microorganisms. A New Synthesis of Ferrichrome; enantio‐FerrichromeThe enantiomer of the natural sideramine ferrichrome was synthesized starting from D‐ornithine. The cyclohexapeptide (D‐Orn)3‐Gly3 was obtained by conventional methods of polypeptide chemistry. For the oxidation of the δ‐amino groups of the D‐ornithine residues to hydroxylamino groups the oxaziridine pathway was successful. The final steps ‐ introduction of the acetyl groups and formation of the iron trihydroxamate complex ‐ followed known procedures. The spectroscopic and chromatographic properties of the crystalline product corresponded to those of natural ferrichrome, the optical rotations and CD. curves being opposite. The biological activity of enantio‐ferrichrome was similar to that of the natural sideramine.
Approaches to the total synthesis of cytochalasans. A convergent synthesis of the octahydroisoindolone moiety related to proxiphomin. Preliminary communication
Authors: Schmidlin Tibur , Tamm Christoph 
Published: December 2004

AbstractThe octahydroisoindolone moiety related to proxiphomin (1) has been synthesized by condensation of N‐benzyloxycarbonyl‐protected D, L‐phenylalaninal (7) with methyl‐(4‐methyl‐sorbyl)‐malonate (11) to yield the branched ethylene derivative 12. Consecutive intramolecular [2+4]‐cycloaddition and lactam ring closure of 12 gave the desired octahydroisoindolone derivative 15, possessing adaptable functional groups for the attachment of the macrocyclic ring system.
15N‐NMR. Spectra of pterins and folic acid derivatives
Authors: Schwotzer Willi , Bieri Jost H. , Viscontini Max , von Philipsborn Wolfgang 
Published: December 2004

Abstract15N‐Chemical shifts of a series of 5, 6, 7, 8‐tetrahydropterins, 7, 8‐dihydropterins and pterins have been measured in acidic solution by means of a probe for 20 mm sample tubes. Included are the relevant data of folic acid (11), 5, 6, 7, 8‐tetrahydrofolic acid (5) and N (5, 10)‐metheno‐5, 6, 7, 8‐tetrahydrofolic acid (6). The different oxidation states are clearly relected in the chemical shifts of N (5) and N (8). Assignment of the nitrogen resonances was achieved by protonation effects (discrimination between N (1) and N (3)) and with the aid of alkyl substitution at C (6) and C(7), to distinguish between N (5) and N (8).
The fluorescence of biliverdin dimethyl ester
Authors: Braslavsky Silvia E. , Holzwarth Alfred R. , Lehner Harald , Schaffner Kurt 
Published: December 2004

AbstractFreshly prepared solutions of biliverdin dimethyl ester (2) in ethanol showed fluorescence maxima at 710 and 770 nm [ΦF = 1.1. 10−4 (room temperature) and 5.0 10−4 (77 K)]. The maxima of monoprotonated 2 at 77 K were shifted to 725 and 806 nm and the quantum yield was increased to 2.6. 10−2. This acid effect was reversible by neutralization with base. When a neutral solution was kept standing in the dark at room temperature, or when an acidic solution was neutralized by base, an additional fluorescence maximum at 500 nm with a mirror image excitation spectrum with λmax = 470 nm developed, which disappeared on addition of acid and which is attributed to a chemical change of 2.
Synthèse d'alcools acétyléniques par alkylation d'hydroxy‐ω‐alkynes‐1
Authors: Flahaut Jacques , Miginiac Philippe 
Published: December 2004

Synthesis of acetylenic alcohols by alkylation of ω‐hydroxy‐1‐alkynesIn liquid ammonia and with lithium amide, the alkylation of an ω‐hydroxyl‐alkyne proceeds with good yield with primary or secondary alcohols and with fair yield with tertiary alcohols. It is a very convenient way to prepare many substituted acetylenic alcohols.
The Radical Anions of [2.2.2.2]Paracyclophane‐1,9,17,25‐tetraene and Some of its Heteroaromatic Analogues
Authors: Gerson Fabian , Huber Walter , Wennerström Olof 
Published: December 2004

AbstractThe radical anions of [2.2.2.2]paracyclophane‐ 1,9,17,25‐tetraene (I), [2] (2, 5)‐furano [2]paracyclo [2] (2,5)furano [2]paracyclophane‐1,8, 16,23‐tetraene (II), [2]‐(2,5)thiopheno [2]paracyclo [2] (2,5)thiopheno [2]paracyclophane‐1,8,16,23‐tetraene (III) and [2.2.2.2](2,5)thiophenophane‐1,8,15,22‐tetraene (IV) have been studied by ESR. and ENDOR. spectroscopy. The assignment of the proton coupling constants, aHμ is to a large extent based on investigations of deuteriated derivatives. These investigations impressively demonstrate the potential of ENDOR. spectroscopy as an analytical tool. The Arrhenius activation energies, Ea, for the rotation of phenylene fragments about the bonds linking them with the ethylenic parts in I⊖ and II⊖ are 36±6 and 28±4 kJ/mol, respectively. The value aHμ of the olefinic protons in I⊖ appears substantially smaller than expected for the corresponding planar radical anion. The hyperfine data for II⊖, III⊖ and IV⊖ are consistent with the conformations which should minimize the deviations of the macrocyclic π‐systems from planarity. In the case of II⊖, tight ion pairs are formed by the radical anion and its counter‐ion, K⊕, in DME, owing to the strong association of the alkali metal cation with one of the furan moieties. An analogous interaction of K⊕ with a thiophene moiety in III⊖ must be weaker, since no effects of ion pairing on the ESR. and ENDOR. spectra have been observed for this radical anion.
Syntheses and Cyclization Reactions of Bifunctional 1,2‐Bis (styryl)benzenes and Some Aza Analogues. Macrocyclic aza compounds. V
Authors: Ehrensperger Carl‐Peter , Heberlein Manfred , Skrabal Peter 
Published: December 2004

AbstractThe syntheses of the bis (styryl)benzenes 4 and 5 and of the aza analogue 3 are described. Diamine 3 and dialdehyde 5 were cyclized to the 14‐membered macrocycles 19 and 27, respectively. Diamine 4 and glyoxal give the 28‐membered macrocycle 28. The cyclizations are discussed.
Photochemische Reaktionen. 98. Mitteilung. Photochemistry of N‐Acylimidazoles. III. Rates and Yields of N→C Acyl Migration and of C(α)‐C(β) Cleavage of Acyl Side Chains
Authors: Yatsunami Takashi , Iwasaki Shigeo 
Published: December 2004

AbstractRelative rates of the photoreactions of 1‐(1), 2‐(2) and 4(5)‐valerylimidazole (3) as well as the yields of photo‐fragmentation product 10 from 1‐(7), 2‐(8) and 4(5)‐stearoylimidazole (9), respectively, were determined. A reaction path via Norrish Type II fragmentation involving the carbonyl group of 1‐acylimidazoles was ruled out.
New Sesquiterpene Alcohols from Galbanum Resin; the occurrence of C (10)‐epi‐sesquiterpenoids
Authors: Thomas Alan F. , Ozainne Michel 
Published: December 2004

Abstract(+)‐β‐Eudesmol (7), (+)‐10‐epi‐elemol (8), (−)‐(Z)‐dihydrofarnesol (3), and an alcohol believed to be a guai‐9‐en‐11‐ol (4) have been isolated from Galbanum resin. Together with (‐)‐β‐dihydroagarofuran (1) and epi‐ligulyl oxide (13) (reported naturally occurring for the first time), 10‐elemol (8) and 10‐epi‐junenol (2) involve the enantiomeric stereochemistry at C (10) compared with β‐eudesmol 7, and guaiol 5, the major sesquiterpene alcohol of Galbanum.