Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• degree of epimerization at C-8a or a less selective Diels–Alder reaction compared to the racemic synthesis. Similar results were obtained within the R-series, starting with R-17. A final Grignard reaction using both ketone stereoisomeric mixtures with methylmagnesium bromide led to the R- and S

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• reactions with water-miscible solvents. Leadbeater and co-workers reported a Grignard reaction in THF, whereby an acidic aqueous phase and a mixture of DCM and hexanes were added to the mixture before phase separation with a Zaiput membrane [62]. The aqueous phase was used to quench the mixture and to

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• multistep flow synthesis of Iloperidone (80) accompanied with a “catch and release” purification protocol. Continuous two-step flow process consisting of Grignard reaction followed by water elimination being the last steps of a multistep flow synthesis of the hydrochloride salt of amitryptiline 84

Strategies for the synthesis of brevipolides

• Yudhi D. Kurniawan and
• A'liyatur Rosyidah

Beilstein J. Org. Chem. 2021, 17, 2399–2416, doi:10.3762/bjoc.17.157

• successfully attained in 97% yield with very high diastereoselectivity (dr 99:1). The free secondary alcohol group was re-protected as MOM ether 70 in 96% yield. After removal of the TBDPS group, the resulting free primary alcohol was oxidized under Dess–Martin conditions followed by Grignard reaction with

Transition-metal-free intramolecular Friedel–Crafts reaction by alkene activation: A method for the synthesis of some novel xanthene derivatives

• Tülay Yıldız,
• İrem Baştaş and
• Hatice Başpınar Küçük

Beilstein J. Org. Chem. 2021, 17, 2203–2208, doi:10.3762/bjoc.17.142

• high yield by refluxing the reactants in the presence of K2CO3 in DMF. 2-Phenoxybenzaldehyde (1a) was converted into secondary alcohol derivative 2a by adding a phenyl group using a Grignard reaction. This reaction was carried out with high yield by adding the freshly prepared Grignard compound of

• synthesized by Grignard reaction of 1a–l and aryl(or alkyl)magnesium bromides. Then 3a–l were prepared by oxidation of 2a–l using PCC. The final alkene compounds 4a–l were obtained by Wittig reaction using Me(Ph)3PBr, t-BuOK, and NaH. All substrates were purified by crystallization or column chromatography

Chemical syntheses and salient features of azulene-containing homo- and copolymers

• Vijayendra S. Shetti

Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139

• -workers [27][28], in 2004, reported the synthesis of conjugated polymers containing azulene and bithiophene units, called poly{1,3-bis[2-(3-alkylthienyl)]azulene} 33–38. The 1,3-bis(3-alkylthienyl)azulene 32, synthesized by the Grignard reaction of 1,3-dibromoazulene (4) with 2-bromo-3-alkylthiophene, was

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Nocarimidazoles C and D, antimicrobial alkanoylimidazoles from a coral-derived actinomycete Kocuria sp.: application of ¹J_C,H coupling constants for the unequivocal determination of substituted imidazoles and stereochemical diversity of anteisoalkyl chains in microbial metabolites

• Md. Rokon Ul Karim,
• Enjuro Harunari,
• Amit Raj Sharma,
• Naoya Oku,
• Kazuaki Akasaka,
• Daisuke Urabe,
• Mada Triandala Sibero and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 2719–2727, doi:10.3762/bjoc.16.222

• 8 and 9, possessing 4-acetyl and 5- or 2-amino substitutions, respectively, were synthesized for comparison, according to the reported procedures (Scheme 1) [25][26][27]. Compound 8 is known as a photolysis product of 6-methylpurine 1-oxide [28], but we prepared it by the Grignard reaction of a

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• parent sumanene (2). Later on, they transformed trione 40 into the corresponding exo-trimethyl derivative 44 by means of a Grignard reaction with MeMgBr via 1,2-addition (Scheme 7). The imination of monoketosumanene 38 as well as triketosumanene 40 has also been reported by these authors to obtain the

Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides

• Mateo Berton,
• Kevin Sheehan,
• Andrea Adamo and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2020, 16, 1343–1356, doi:10.3762/bjoc.16.115

• exothermic Grignard reaction done at 25 ºC was not fully dissipated by the heat exchanger (≈10 ºC increment). To better understand this exothermic process, we decided to measure the temperature evolution during the conversion of EtBr (0.5 M) at a 0.5 mL/min flow rate with no heat controller. Three

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

• Iwona E. Głowacka,
• Aleksandra Trocha,
• Andrzej E. Wróblewski and
• Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

• groups were introduced by Grignard reaction while the hydroxymethyl fragment was derived from the aziridine ring opening to produce (2S,1'R)-123. N-Debenzylation was accompanied with deoxygenation at the hydroxydiphenylmethyl site to give N-Boc-3,3-diphenylalaninol ((R)-124) which was oxidized with Jones

Stereochemical investigations on the biosynthesis of achiral (Z)-γ-bisabolene in Cryptosporangium arvum

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2019, 15, 789–794, doi:10.3762/bjoc.15.75

• Grignard reaction of geranylacetone with vinylmagnesium bromide. The two NPP samples featuring a well-defined stereocentre, and (rac)-NPP, were incubated with recombinant BbS, the experiments were extracted with hexane and analysed by GC–MS (Figure 3). A selective product formation was observed for the two

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

Gram-scale preparation of negative-type liquid crystals with a CF₂CF₂-carbocycle unit via an improved short-step synthetic protocol

• Tatsuya Kumon,
• Shohei Hashishita,
• Takumi Kida,
• Shigeyuki Yamada,
• Takashi Ishihara and
• Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 148–154, doi:10.3762/bjoc.14.10

• , generating the lactone Int-H. Accordingly, Int-H could undergo a second Grignard reaction with vinylmagnesium chloride present in the reaction mixture, resulting in the formation of Int-I. The latter intermediate, Int-I which is also in equilibrium with Int-J at reflux temperature, can react with the vinylic

• reported negative-type liquid crystals containing a CF2CF2-carbocycle. (a) Expected products of over-reaction in the Grignard reaction of dimethyl tetrafluorosuccinate (7) with 4-n-propylmagnesium bromide (reaction step 7→6). (b) Mechanism for the 7→6 reaction step. Improved short-step synthetic protocol

Volatiles from the tropical ascomycete Daldinia clavata (Hypoxylaceae, Xylariales)

• Tao Wang,
• Kathrin I. Mohr,
• Marc Stadler and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2018, 14, 135–147, doi:10.3762/bjoc.14.9

• D’Amico [37] and proceeds with inversion of configuration at C-2. Grignard reaction with ethylmagnesium bromide to 29a, PCC oxidation to 30a and deprotection with HF-pyridine gave access to (4R,5S,6S)-11c with an overall yield of 7% via seven steps. The 13C NMR data in CDCl3 (cf. Supporting Information

Chemical probes for competitive profiling of the quorum sensing signal synthase PqsD of Pseudomonas aeruginosa

• Michaela Prothiwa,
• Dávid Szamosvári,
• Sandra Glasmacher and
• Thomas Böttcher

Beilstein J. Org. Chem. 2016, 12, 2784–2792, doi:10.3762/bjoc.12.277

• α-chloroacetamide probes CA1–3 by reaction with chloroacetyl chloride (Figure 2B). The α,β-unsaturated ketone probe UK1 was synthesized via the Weinreb–Nahm amide in a Grignard reaction with vinylmagnesium bromide (Figure 2C). An overview of the small ABPP probe library is given in Figure 2D. Active

Practical synthetic strategies towards lipophilic 6-iodotetrahydroquinolines and -dihydroquinolines

• David R. Chisholm,
• Garr-Layy Zhou,
• Ehmke Pohl,
• Roy Valentine and
• Andrew Whiting

Beilstein J. Org. Chem. 2016, 12, 1851–1862, doi:10.3762/bjoc.12.174

• chromatography or distillation. Using one equivalent lowered the yield, but minimised bis-adduct formation, which allowed facile purification by short path distillation on larger scales. Compound 8 was functionalised to the tertiary alcohol 9 by a Grignard reaction with MeMgBr, which could be directly cyclised

Diastereoselective synthesis of new O-alkylated and C-branched inositols and their corresponding fluoro analogues

• Charlotte Collet,
• Françoise Chrétien,
• Yves Chapleur and
• Sandrine Lamandé-Langle

Beilstein J. Org. Chem. 2016, 12, 353–361, doi:10.3762/bjoc.12.39

• bearing a hydroxylated arm The synthesis of C-branched inositols was investigated using two different arm lengths, with either two or three carbon atoms. The introduction of these substituents was performed by a Grignard reaction in THF with vinyl- or allylmagnesium bromide on benzylated myo-2-inosose 7

Study on the synthesis of the cyclopenta[f]indole core of raputindole A

• Nils Marsch,
• Mario Kock and
• Thomas Lindel

Beilstein J. Org. Chem. 2016, 12, 334–342, doi:10.3762/bjoc.12.36

• , which was synthesized via Heck reaction with but-3-en-2-ol (5, 89%) in the presence of LiCl, inspired by a procedure by Camp and coworkers [36]. Propargyl bisindole 7 was obtained after conversion of 4 (2 equiv) to the magnesium acetylide (iPrMgCl in THF) and Grignard reaction with ketone 6. Due to the

Design and synthesis of hybrid cyclophanes containing thiophene and indole units via Grignard reaction, Fischer indolization and ring-closing metathesis as key steps

• Sambasivarao Kotha,
• Ajay Kumar Chinnam and
• Mukesh E. Shirbhate

Beilstein J. Org. Chem. 2015, 11, 1514–1519, doi:10.3762/bjoc.11.165

• via Grignard addition, Fischer indolization and ring-closing metathesis as key steps. Keywords: cyclophane; Grignard reaction; Fischer indolization; ring-closing metathesis; Introduction Modern olefin metathesis catalysts enable a late stage ring-closing step starting with bisolefinic substrates

• . Later, it was refluxed over and distilled from P2O5 and stored over sodium wire. Other reagents and solvents were purchased from commercial suppliers and used without further purification. General procedure for the Grignard reaction Analogously as described in [23], Mg turnings and iodine in THF were

Spiro annulation of cage polycycles via Grignard reaction and ring-closing metathesis as key steps

• Sambasivarao Kotha,
• Mohammad Saifuddin,
• Rashid Ali and
• Gaddamedi Sreevani

Beilstein J. Org. Chem. 2015, 11, 1367–1372, doi:10.3762/bjoc.11.147

• ) reaction as a key step is described. The structures of three new cage compounds 7, 12 and 18 were confirmed by single crystal X-ray diffraction studies. Keywords: cage molecules; Diels–Alder reaction; Grignard reaction; ring-closing metathesis; spirocycles; Introduction Design and synthesis of

• product 20 (Scheme 6). Conclusion In summary, we have demonstrated a new approach to intricate C2-symmetric cage bis-spirocyclic pyran derivative 7 through an allyl Grignard reaction and an RCM sequence. The strategy demonstrated here involves an atom economic process. The synthetic sequence demonstrated

• Claisen rearrangement and RCM as key steps [21][30]. Here, we have prepared the cage dione 10 by the known route involving two atom-economic protocols such as Diels–Alder reaction and [2 + 2] photocycloaddition [42][43][44][45] (Scheme 1). Later, the hexacyclic cage dione 10 was subjected to a Grignard

Are D-manno-configured Amadori products ligands of the bacterial lectin FimH?

• Tobias-Elias Gloe,
• Insa Stamer,
• Cornelia Hojnik,
• Tanja M. Wrodnigg and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2015, 11, 1096–1104, doi:10.3762/bjoc.11.123

• easily obtained by a Grignard reaction of 2,3:5,6-di-O-isopropylidene-D-mannose employing commercially available vinylmagnesium bromide (Scheme 2) [16][17]. This C-elongation approach leads to a mixture of C-2 diastereomers, however, during the Amadori rearrangement this centre is converted to a keto

Properties of PTFE tape as a semipermeable membrane in fluorous reactions

• Brendon A. Parsons,
• Olivia Lin Smith,
• Myeong Chae and
• Veljko Dragojlovic

Beilstein J. Org. Chem. 2015, 11, 980–993, doi:10.3762/bjoc.11.110

• was followed by numerous improved and modified designs including a quadraphasic/tetraphasic PV reaction [10], a photochemical PV reaction [11][12], a stacked phase-vanishing reaction [13], a PV reaction on neat substrates [11][14][15][16] and, most recently, a Grignard reaction [17]. Jana and Verkade

Design and synthesis of novel bis-annulated caged polycycles via ring-closing metathesis: pushpakenediol

• Sambasivarao Kotha and
• Mirtunjay Kumar Dipak

Beilstein J. Org. Chem. 2014, 10, 2664–2670, doi:10.3762/bjoc.10.280

• ’ 1st and 2nd generation catalysts at rt as well as under reflux conditions. However, even the presence of ethylene during the metathesis sequence did not deliver the expected product, and the starting material remained unaltered (Scheme 5). Conclusion We demonstrated that the Grignard reaction in

Reaction of selected carbohydrate aldehydes with benzylmagnesium halides: benzyl versus o-tolyl rearrangement

• Maroš Bella,
• Bohumil Steiner,
• Vratislav Langer and
• Miroslav Koóš

Beilstein J. Org. Chem. 2014, 10, 1942–1950, doi:10.3762/bjoc.10.202

• Technology, 412 96 Göteborg, Sweden 10.3762/bjoc.10.202 Abstract The Grignard reaction of 2,3-O-isopropylidene-α-D-lyxo-pentodialdo-1,4-furanoside and benzylmagnesium chloride (or bromide) afforded a non-separable mixture of diastereomeric benzyl carbinols and diastereomeric o-tolyl carbinols. The latter

• possible mechanism for the Grignard reaction leading to the benzyl→o-tolyl rearrangement is also proposed. Keywords: aldehyde; benzyl versus o-tolyl; carbohydrate; Grignard reaction; rearrangement; X-ray crystallography; Introduction One of the most popular synthetic routes leading to the formation of

• possible the preparation of a series of useful carbohydrate derivatives [1][2][3][4][5][6][7][8]. Despite the demonstrable advantages of the Grignard reaction, there remain, in addition to the recognised drawbacks, some new unexpected impediments limiting its application in the synthesis of branched