bluuebunny/crossref_metadata_2025_split huggingface dataset:
Singlet‐Oxygen Ene Reactions of (E)‐4‐Propyl[1,1,‐2H3]oct‐4‐ene. Short Communication
Authors: Rautenstrauch Valentin , Thommen Walter , Schulte‐Elte Karl H. 
Published: December 2004

AbstractRose bengal‐sensitized photooxygenation of 4‐propyl‐4‐octene (1) in MeOH/Me2CHOH 1:1 (v/v) and MeOH/H2O 95:5 followed by reduction gave (E)‐4‐propyl‐5‐octen‐4‐ol (4), its (Z)‐isomer 5, (E)‐5‐propyl‐5‐octen‐4‐ol (6), and its (Z)‐isomer 7. Analogously, (E)‐4‐propyl[1,1,1‐2H3]oct‐4‐ene (2) gave (E)‐4‐propyl[1,1,1‐2H3]oct‐5‐en‐4‐ol (14), its (Z)‐isomer 15, (E)‐5‐[3′,3′,3′‐2H3]propyl‐5‐octen‐4‐ol (16), its (Z)‐isomer 17, and the corresponding [8,8,8‐2H3]‐isomers 18 and 19 (see Scheme 1). The proportions of 4–7 were carefully determined by GC between 10% and 85% conversion of 1 and were constant within this range. The labeled substrate 2 was photooxygenated in two high‐conversion experiments, and after reduction, the ratios 16/18 and 17/19 were determined by NMR. Isotope effects in 2 were neglected and the proportions of corresponding products from 1 and 2 assumed to be similar (% 4 ≈︁ % 14; % 5 ≈︁ % 15; % 6 ≈︁ % (16 + 18): % 7 ≈︁ % (17 + 19)). Combination of these proportions with the ratios 16/18 and 17/19 led to an estimate of the proportions of hydroperoxides formed from 2. Accordingly, singlet oxygen ene additions at the disubstituted side of 2 are preferred (ca. 90%). The previously studied trisubstituted olefins 20–25 exhibited the same preference, but had both CH3 and higher alkyl substituents on the double bond. In these substrates, CH3 groups syn to the lone alkyl or CH3 group appear to be more reactive than CH2 groups at that site beyond a statistical bias.
Die Synthese von 6,7‐Dihydro‐2H‐pyrimido[6, 1‐a]isochinolin‐4(3H)‐onen und analogen Verbindungen und deren Wirkung als Blutpättchenaggregationshemmer
Authors: Kienzle Frank , Bounameaux Yves , Minder Rudolf E. , Muggli Reto 
Published: December 2004

Synthesis of 6,7‐Dihydro‐2H‐pyrimido[6,1‐a]isoquinolin‐4(3H)‐ones and Analogous Compounds and their Activity as Blood‐Platelet InhibitorsThe synthesis of 6,7‐dihydro‐2H‐pyrimido[6,1‐a]isoquinolin‐4(3H)‐ones and of analogous compounds is described. These compounds are powerful phosphodiesterase inhibitors and, therefore, inhibit blood‐platelet aggregation independent of the agonist. They exhibit, too, cardiac activities. However, there is evidence for selective action. A structure‐activity relationship for platelet‐aggregation inhibitors is discussed.
Chlorine Dioxide as an Electron‐Transfer Oxidant of Olefins. Preliminary Communication
Authors: Rav‐Acha Chaim , Choshen (Goldstein) Ehud , Sarel Shalom 
Published: December 2004

AbstractThe kinetics and product studies of oxidation of eight olefins 1‐8 by ClO2 in H2O in the pH range 3‐7 are described. The reaction is faster as the pH decreases. At pH < 4, ClO2 reacts equimolarly with olefins to yield isomeric mixtures of chlorohydrines and 1,2‐dioxygenated products, following the equation: magnified image The order of reactivity is: (E)‐stilbene > indene > β‐methylstyrene > acenaphthylene > α‐methylstyrene > styrene > cyclohexene > allylbenzene. A multi‐stage radical‐cation mechanism is proposed, in which an initial reversible protonation:

is followed by an electron‐transfer stage (rate‐determining): magnified image The cation‐radical thus produced, adds rapidly an additional ClO2 to form dioxygenated products. The chlorohydrines most likely arise from HClO additions to the olefinic double bonds, which, in turn, generate from dismutation of 2 HClO2 into HClO + H+ + ClO.
Butanolide und Butenolide durch intramolekulare En‐Reaktion bei der Thermolyse von Propargyl‐propiolaten
Authors: Bilinski Vanda , Karpf Martin , Dreiding André S. 
Published: December 2004

Butanolides and Butenolides by Intramolecular Ene‐Reaction during Thermolysis of Propargyl PropiolatesGas‐phase flow thermolysis of 2‐butynyl propynoate (1) and 2‐propynyl 2‐butynoate (2) at 550° afforded 3‐ethynyl‐2‐methyl‐2‐buten‐4‐olide (4, 85%) and 2‐ethynyl‐3‐methyl‐2‐buten‐4‐olide (5, 80%), respectively. Their formation presumably entails an ene reaction between the methylacetylenic and the acetylenic functions of the diyne esters 1 and 2 to give the two methyliden‐vinyliden‐butanolides 10 and 11 as intermediates, followed by a [1,5]‐H shift to 4 and 5. At 400–450°, the gas phase flow thermolysis of 1 and 2 led to the dimers 16 (77%) and 17 (6%), respectively. These products resulted from the Diels‐Alder dimerization of the above mentioned intermediates 10 and 11. The regioselectivity of this dimerization is determined by a ‘head‐to‐head’ approach, with the double bond conjugated to the carbonyl group acting as the dienophile in both cases. The low yield of 17 from 2 is probably due to a further Diels‐Alder reaction of the dimer 17 with its precursor 11, yielding a trimer 18 (8% isolated). This process is not possible when starting with 1, which explains the higher yield of 16. The gas phase flow thermolysis of 2‐butynyl 2‐butynoate (3) at 550° afforded a mixture of four isomeric products, namely the two monocyclic ethynyl‐butenolides 6 and 7 and the two bicyclic vinyl‐butenolides 8 and 9. The formations of 6–9 are also rationalizable by initial ene‐reactions, in this case two alternative ones, each involving one of the two CH3 groups of 3. This leads to two alkylidene‐vinylidene‐butenolides, namely 12 and 13. A [1,5]‐H shift converts 12 into 6 and 13 into 7. A competing alternative [1,5]‐H shift transforms both 12 and 13 to the triene 14, which electrocyclizes to the cyclohexadiene 15. The latter undergoes two alternative [1,5]‐H shifts to yield 8 and 9.
Intermolecular [4 + 2]‐Cycloadditions of Nitroalkenes with Cyclic Olefins. Transformations of Cyclic Nitronates
Authors: Denmark Scott E. , Cramer Christopher J. , Sternberg Jeffrey A. 
Published: December 2004

AbstractNitrocyclohexene undergoes facile SnCl4‐induced, [4 + 2]‐cycloadditions with simple cycloalkenes to produce nitronates. The nitronates can be transformed sterospecifically into a number of other functional groups (alcohol, ketone, oxime, amine) by hydrolytic, reductive, and oxidative processes. The mechanism of the [4 + 2]‐cycloaddition is believed to involve formation of a zwitterionic intermediate which can collapse via competing pathways to form the observed products. 1,3‐Dipolar cycloadditions of the nitronates are described.
Kombinierte NOE‐ und Entkopplungsexperimente zur selektiven H‐NMR‐Detektion: Anwendung auf ein stereochemisches Problem
Authors: Bigler Peter 
Published: December 2004

Combined NOE and Decoupling Experiments for the Selective H‐NMR Detection: Application to a Stereochemical ProblemThe successful solution of complex stereochemical problems by NMR methods often requires scalar (J) and dipolar (NOE) data. A modern method, improved with respect to sensitivity and selectivity, which yields both scalar and dipolar informations is proposed, and an application to configurational analysis is demonstrated. The method is based on NOE effects for the detection of selected protons and homonuclear decoupling for improved resolution.
Metal complexes with macrocyclic ligands. Part XXV. One‐step synthesis of mono‐N‐substituted azamacrocycles with a carboxylic group in the side‐chain and their complexes with Cu2+ and Ni2+
Authors: Studer Martin , Kaden Thomas A. 
Published: December 2004

AbstractMono‐N‐substituted azamacrocycles 2–7, containing a carboxyalkyl or carboxyaryl side‐chain, are obtained by reacting a five‐fold excess of the macrocycle with 1 equiv. of a suitable halogenocarboxylic acid in alkaline aqueous EtOH. For halogenocarboxylic acids, which easily lactonize under alkaline conditions, a variant with the corresponding ester or nitrile as alkylating agent is also described. The salient point of this synthesis lies in the use of an excess of the macrocycle over the alkylating agent, thus reducing the amount of polyalkylation to a minimum, and in the easy separation of the excess of unreacted educt from the aminocarboxylic acid. These new ligands form Ni2+ and Cu2+ complexes, the spectral properties of which have been studied. In the case of the Cu2+ complexes with ligand 2, 3, and 6, a pH‐dependent color change is observed. This is explained with an equilibrium between a species, in which the carboxylate group is bound to the metal, and one, in which it is protonated and non‐coordinated. In the case of the Ni2+ complexes with the same ligands, only the species with a coordinated carboxylate was observed. In the Cu2+ and Ni2+ complexes with ligands 4 and 5, however, the carboxylate group does not coordinate at all, because of the length or the special structure of the chain.
Norbornanes. Part 18. Inductive Charge Dispersal in the Solvolyses of 4‐ and 5‐Substituted 2‐Norbornyl p‐Toluenesulfonates
Authors: Fuso Francesco , Grob Cyril A. , Sawlewicz Pawel , Yao Guo Wei 
Published: December 2004

AbstractThe solvolysis rates and products of 4‐ and 5‐exo‐substituted 2‐exo‐ and 2‐endo‐norbornyl tosylates 9 and 10, respectively, are reported. The logarithms of the rate constants (log k) correlate linearly with the inductive constants σ for the substituents. A comparison of the reaction constants p1 for the 4‐, 5‐, 6‐, and 7‐substituted 2‐exo‐ and 2‐endo‐tosylates 9, 10, 1, and 2 respectively, indicates that inductivity is higher for 2‐exo‐ionization than for 2‐endo‐ionization in all series. This observation is attributed to the more favorable alignment of neighbouring C‐atoms for dorsal participation in exo‐ionization, especially, in the case of C(6).
Molecular Anion Binding and Substrate Photooxidation in Visible Light by 2,7‐Diazapyrenium Cations
Authors: Blacker A. John , Jazwinski Jaroslaw , Lehn Jean‐Marie 
Published: December 2004

AbstractThe 2,7‐diazapyrenium group (DAP2+) combines the features of pyrene, of methylviologen, and of nucleicacid intercalators and may thus present a variety of interesting properties. The cations 1 and 2 and the bis‐diazapyrenium species 3 have been synthesized and shown to bind molecular anions like aromatic polycarboxylates, giving rise to pronounced shifts of 1H‐NMR signals, modifications of UV/VIS absorption spectra, and quenching of fluorescence. The complexes formed probably have a face‐to‐face structure, and their stability constants are remarkably high, in particular for the bis‐diazapyrenium cation 3 which is susceptible to form intercalative chelate complexes such as 9(log Ks ≈ 3 for 1, up to ca. 7 or more for 3a). Neutral molecules like adenine are also bound, but much less strongly. Visible‐light irradiation of Me2DAP2+ (1) in presence of various electron donors, such as EDTA, gives the reduced species Me2DAP+ wich has been characterized by UV/VIS and ESR spectroscopy. The results indicate that Me2DAP2+ (1) functions as a methylviologen analogue, photoactive in visible light. Thus 2,7‐diazapyrenium cations are attractive subunits for incorporation into macropolycyclic structures to give photo‐ and electroactive receptor molecules.
Norbornanes. Part 19. The Inductive Model for Norbornyl Cation Formation
Authors: Altmann‐Schaffner Eva , Grob Cyril A. 
Published: December 2004

AbstractTwo CH3 groups at C(6) of 2‐exo‐ (10a) and 2‐endo‐norbornyl p‐toluenesulfonate 11a lower their solvolysis rates in 80% EtOH by factors of 28 and 16, respectively. A spirocyclopropyl group including C(6), as in 21a and 22a, reduces the rate of exo‐ and endo‐ionization by factors of 250 and 8, respectively. The geminally dimethyl‐substituted tosylates 10a and 11a yield the 2‐exo‐alcohol 10b, whereas the spirocyclopropyl‐substituted tosylates 21a and 22a furnish rearranged 3‐brendanol 23. These findings are readily rationalized by the inductive model, according to which norbornyl cation formation is controlled by the inductive effect of dorsal substituents.
Enantionselektive Synthese des L‐Threonins
Authors: Soukup Milan , Wipf Beat , Hochuli Erich , Leuenberger Hans G. W. 
Published: December 2004

An Enantionselective Synthesis of L‐ThreonineAn enantioselective synthesis of L‐threonine (1) is described. Racemic ethyl 2‐acetamido‐3‐oxobutyrate (6) was synthesized from ethyl acetoacetate (2) [4][5] and then transformed to the epimeric optically active alcohols 7a and 7b by microbiological reduction with Saccharomyces rouxii. The Mixture 7a/7b could be converted to 1 by slightly modified, known Methods in a yield of ca. 52% with respect to 7a/7b.
Elektrochemische Oxidation von (S)‐Äpfelsäure‐Derivaten: ein Weg zu enantiomerenreinen alkylierten Malonaldehydsäure‐estern
Authors: Renaud Philippe , Hürzeler Marianne , Seebach Dieter 
Published: December 2004

Electrochemical Oxidation of (S)‐Malic‐Acid Derivatives: a Route to Enantiomerically Pure Alkylmalonaldehydic EstersThe 3,3‐dialkymalic‐acid diesters, prepared by the previously described diastereoselective alkylations through dilithium alkoxide enolates, are saponified to the monoesters containing a free α‐hydroxycarboxylic‐acid moiety(Scheme 3). The monoesters are subjected to electrochemical oxidative decarboxylation in MeOH. If the intermediate monoacids are purified, the malonaldehydic esters (2‐formy1‐2‐alkylcaroxylates) Obtained by this procedure are enantiomerically pure; they have the same structural features, i.e. two enantiotopic functionalized branches on the (persubstituted) stereogenic center, as the well known 3‐hydroxy‐2‐methylpropanoic acid (‘Roche acid’) which was employed frequently as a starting material for the preparation of either enantiomer of various target molecules.
Synthese eines Nickel(II)‐B,C,D‐hexadehydrocorrinats durch (A→D)‐Cyclisierung
Authors: Montforts Franz‐Peter , Bats Jan W. 
Published: December 2004

Synthesis of a Nickel(II) B,C,D‐Hexadehydrocorrinate by (A→D)‐Ring ClosureThe B,C,D‐hexadehydrocorrin of type 10 fills a gap in the corrin family whose members can occur at different oxidation levels. We report here on the synthesis of a correspondingly protected secocorrin 23 and its convenient cyclization to 10
Antimykotisch wirksame Imidazolyl‐alkene: Synthese und Röntgenstrukturanalyse von Omoconazol
Authors: Thiele Kurt , Zirngibl Ludwig , Pfenninger Max H. , Egli Martin , Dobler Max 
Published: December 2004

Antimycotic Imidazolyl‐alkenes: Synthesis and X‐Ray Crystal Structure of OmoconazolThe synthesis of omoconazol 4 from 2′,4′‐dichloro‐α‐(1H‐imidazol‐1‐yl)propiophenon (5) and 1‐bromo‐2‐(4‐chlorophenoxy)ethane (6) is described. Omoconazol, C20H17Cl3N2O2, crystallises in the monoclinic space group P21/n, a = 14.329, b = 8.703, c = 16.791 Å, β = 105.75°. The crystal structure showed that omoconazol has the (Z)‐configuration, in accordance with previous NMR results.
Copper(II) Triflate, a New Reagent for Mild Dehydration of Alcohols: Synthetic Usefulness and Mechanistic Insight
Authors: Laali Khosrow , Gerzina Robert J. , Flajnik Christine M. , Geric Cynthia M. , Dombroski Ann Marie 
Published: December 2004

AbstractThe effectiveness of copper(II) triflate (copper(II) trifluoromethanesulfonate) as a new dehydrating reagent for a variety of alcohols has been demonstrated. Based on several control experiments, a possible mechanism is suggested.
Verapliquinones: Novel Diprenylquinones from an Aplidium sp. (Ascidiacea) of Ile‐Verte Waters, Brittany
Authors: Guella Graziano , Mancini Ines , Pietra Francesco 
Published: December 2004

AbstractAn Aplidium sp. (Ascidiacea), collected in French Atlantic waters near the Ile Verte, is shown to contain verapliquinone B (2) and verapliquinone D (6) as the first examples of linear diprenylquinones of the neryl type, besides their respective isomers 1 and 5 of the geranyl type.
Syntheses of (+)‐ and (–)‐Methyl 8‐Epinonactate and (+)‐ and (–)‐Methyl Nonactate
Authors: Warm Aleksander , Vogel Pierre 
Published: December 2004

AbstractIn four synthetic steps, (+)‐ and (–)‐methyl 8‐epinonactate ((+)‐ and (–)−4) have been derived from (+)‐ and (–)‐7‐oxabicyclo[2.2.1]heptan‐2‐one ((+)‐ and (–)−9), respectively. The (+)‐ and (–)‐methyl nonactate ((+)‐ and (–)−3) were obtained from (+)‐ and (–)−4, respectively, by Mitsunobu displacement reactions. Optical resolution of (±)−9 via chromatographic separation of the corresponding N‐methyl‐S‐alkyl‐S‐phenylsulfoximides 24 and 25 yielded the starting materials (+)‐ and (–)−9, respectively.
Photolactonisierung: Ein neuer synthetischer Zugang zu Makroliden
Authors: Quinkert Gerhard , Billhardt Uta‐Maria , Jakob Harald , Fischer Gerd , Glenneberg Jürgen , Nagler Peter , Autze Volker , Heim Nana , Wacker Manfred , Schwalbe Thomas , Kurth Yvonne , Bats Jan W. , Dürner Gerd , Zimmermann Gottfried , Kessler Horst 
Published: December 2004

Photolactonization: A Novel Synthetic Entry to Macrolideso‐Quinol acetates, hydroxyalkylated at C(6), are easily accessible from simple phenols by Wessely acetoxylation (preferentially catalyzed by BF3). On UV irradiation (in the presence of an appropriate tertiary amine), they are smoothly converted to macrocyclic lactones. Subtle conditions have been elaborated to lead to high overall yields, and the scope of the conversion of phenols to macrolides has been elucidated.
Field‐Desorption Mass Spectra of Fern Phloroglucinols Containing Three to Six Ring Constituents
Authors: Richter Wilhelm J. , Raschdorf F. , v. Euw Josef , Reichstein Tadeus , Widén Carl‐Johan 
Published: December 2004

AbstractIt has been previously shown that the structural analysis of the title compounds by electron‐impact ionization (EI)mass spectrometry is complicated by extensive, if not complete, thermal rottlerone‐type rearrangement and/or fragmentation reactions. The use of a ‘softer’ ionization technique such as field desorption (FD) is, therefore, required in order that these compounds may be characterized in terms of their molecular size and composition. In this report, the FD mass spectra of typical representatives of this class of compounds are described along with the attempted suppression of undesirable thermal reactions by the optimization of the emitter temperatures.
On the Photochemistry of 12,13‐Didehydrosqualene
Authors: McWhorter William W. , Jaun Bernhard 
Published: December 2004

AbstractThe photochemical formation of bicyclooctenes b from 12,13‐didehydrosqualene (1) upon irradiation at wavelengths longer than 290 nm is reported. The same photoreaction is also observed with trienes 7 and 8 which like 1 have a remote double bond two C‐atoms removed from the triene system. A configurational assignment for bicyclooctene 10 obtained from 8 and a mechanism for the observed photochemical reaction are proposed.
Diels‐Alder‐Reaktionen von 2,4‐Bis{[(tert‐butyl)dimethylsilyl]oxy}‐3‐aza‐1,3‐pentadien mit Heterodienophilen
Authors: Ried Walter , Reiher Uwe , Jan W. Bats 
Published: December 2004

AbstractDiels‐Alder Reactions of 2,4‐Bis{[(tert‐Butyl)dimethylsilyl]oxy}‐3‐aza‐‐1,3‐pentadien with HeterodienophilesThe 2,4‐bis{[(tert‐butyl)dimethylsilyl]oxy}‐3‐aza‐1,3‐pentadien(2) reacts via the Diels‐Alder adducts 3, 6a‐c, and 8a, b, which cannot be isolated, giving the triazines 4, 7a‐c, and the oxadiazines 9a, b. The hydrolysis of 4 in MeOH affords the N‐acetyl‐acetamid derivative 5. The formula of 9a is proven by an X‐ray‐structure analysis.
Novel Synthesis of Agaritine, a 4‐Hydrazinobenzyl‐Alcohol Derivative Occurring in Agaricaceae
Authors: Datta Subir , Hoesch Lienhard 
Published: December 2004

AbstractThe 4‐hydrazinobenzyl alcohol (3 was prepared (58%)) by diiobutylaluminiumhydride reduction of methyl 4‐hydrazinobenzoate (4), whereas LiA1H4 or LiBh4 reduction of4 proceeded further to yield (via intermediate 3) (4‐tolyl)hydrazine (5). The alcohol 3 was stable under O2‐free conditions and exhibited no tendency to eliminate H2O, neither thermally nor with H+ catalysis. Oxidation of 3 with SeO2 yielded 4‐(hydroxymethyl)benzine‐diazonium ion (8), identified by its azo coupling product 9 with 2‐naphthol. Condensation of 3 with 1‐benzyl 5‐Hydrogen N‐(benzyloxycarbonyl)‐L‐glutamate (10) in presence of dicyclohexylcarbodiimide afforded 81% of N2‐(benzyloxycarbonyl)‐L‐ glutamic acid 1‐(benzyl‐ester) 5‐{2‐[4‐(hydroxymethyl)phenyl]hydrazide} (11) which upon controlled hydrogenolysis (quinoline‐sulfur‐poisoned Pd/C catalyst) gave 82% of L‐Glutamic acid 5‐{2‐[4‐(hydroxymethyl)phenyl] hydrazide} (1), i. e. agaritine, a metabolite of Agaricus bisporus. Without poisoning of the catalyst, hydrogenolysis of (11) yielded L‐glutamic acid 5‐[2‐(4‐tolyl)hydrazide] (12).
Nucleotides. Part XXVII Bis[2‐(p‐nitrophenyl)ethyl] Phosphorochloridate, a New Versatile Phosphorylating Agent in Nucleotide Chemistry
Authors: Himmelsbach Frank , Charubala Ramamurthy , Pfleiderer Wolfgang 
Published: December 2004

AbstractA new, versatile phosphorylating agent, bis[2‐(p‐nitrophenyl)ethyl] phosphorochloridate (3), has been prepared and is used for 3′‐ and/or 5′‐phosphorylations of nucleosides. The resulting bis[2‐(p‐nitrophenyl)ethyl] phosphotriesters are versatile synthons in oligonucleotide synthesis leading finally to 3′‐ and/or 5′‐terminated monophosphates in excellent yields.
Einfache Umwandlung von(–)‐(R)‐3‐Hydroxybuttersäure in das (+)‐(S)‐Enantiomere und dessen Lacton(‒)‐(S)‐4‐Methyloxetan‐2‐on
Authors: Griesbeck Axel , Seebach Dieter 
Published: December 2004

AbstractSimple Conversion of (R)‐3‐Hydroxybutanoic Acid to the (S)‐Enantiomer and its Lactone (–)‐(S)‐4‐Methylixetan‐2‐oneCondensation of (R)‐3‐hydroxybutanoic acid (1) with ethyl orthoacetate gives a 2‐ethoxy‐substituted (1,3)dioxanone 2 which is thermally labile: at ca. 100°, two competing processes commence, one leading to ethyl (R)‐3‐acetoxybutanoate (3), the other one ‐ with complete inversion of configuration ‐ to the (S)‐4‐methylixetan‐2‐one (4) and ethyl acetate. These can be readily separated by fractional distillation. Thus, enantiomerically pure (S)‐3‐hydroxybutanoic acid (ent‐1) and l‐2‐alkyl‐3‐hydroxybutanoic‐acid derivatives (such as 6 and 8) become available from the biopolymer PHB, the precursor to the acid 1.
Diasteroselektive Hydroxyalkylierungen in 1‐Stellung von Tetrahydroisochinolinen und Synthese von Aporphin‐, Protoberberin‐ und Phthalid‐Alkaloider
Authors: Seebach Dieter , Isabelle M. P. Huber , Max A. Syfrig 
Published: December 2004

Diastereoselective Hydroxyalkylations in Position 1 of Tetrahydroisoquinolines and Synthesis of Aporphine, Protoberberine, and Pathalide AlkaloidsUnsubstituted and 6,7‐dialkoxy‐N‐pivaloyl‐tetrahydroisoquinolines 1–3 are converted to 1‐bromomagnesium derivatives by sequential treatment with t‐BuLi (−75°/THF) and MBr2.OEt2. Addition of the metalated tetrahydroisoquinolines to aliphatic or aromatic aldehydes occurs with relative topicity ul (Scheme 2). The 1‐hydroxyalkylated 2‐pivaloyl‐tetrahydroisoquinolines a of u‐configuration thus obtained (14 examples) can be converted to free aminoalcohols c of either l‐or u‐configuration (9 examples; Scheme 3). The depivaloylation with retention (→ u‐c) is best achieved by heating in EtOH/KOH, the conversion to 1‐aminoalcohols l‐c by treatment with CF3COOH/(CF3CO)2O (→ l,‐pivalates l‐b), followed by alkaline saponification or by LiAlH4 reduction of the esters. The configuration of the products is assigned by 1H‐NMR spectroscopy, by X‐ray crystal structure analysis, by chemical correlation, and by comparison of the chemical properties of the l‐ and the u‐isomers. The diastereoselective hydroxybenzylation of the tetrahydroisoquinoline is used for short syntheses of ushinsunine/oliveroline (Scheme 4), β‐hydrastine, and ophiocarpine/epiopliocarpine (Scheme 6; aporphine, phthalide, and protoberberine alkaloids, respectively).