A new member of the fusaricidin family – structure elucidation and synthesis of fusaricidin E

• Marcel Reimann,
• Louis P. Sandjo,
• Luis Antelo,
• Eckhard Thines,
• Isabella Siepe and
• Till Opatz

Beilstein J. Org. Chem. 2017, 13, 1430–1438, doi:10.3762/bjoc.13.140

• ). Retrosynthetic plan For our synthesis, a novel and efficient access to the GHPD side chain starting from erucamide (6) as an inexpensive natural source for the required C13-fragment was developed. After ozonolysis of the Fmoc-protected amine obtained by reduction and alkoxycarbonylation from 6, the stereocenter

• should be generated by nucleophilic addition of an allyl anion equivalent to the resulting aldehyde 5. Guanidine formation and ozonolysis with subsequent oxidation to the carboxylic acid would then furnish the protected GHPD side chain building block 3 which can then be coupled to the cyclodepsipeptide

• hydride, followed by Fmoc-protection and ozonolysis furnished aldehyde 5 in 57% yield over three steps (Scheme 2). The homoallylic alcohol was prepared by an enantioselective Duthaler–Hafner allylation [13] with the titanium-complex 15 in high yield and 94% ee. Attempts to perform a catalytic Keck

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

• Daniel Wiegmann,
• Stefan Koppermann,
• Marius Wirth,
• Giuliana Niro,
• Kristin Leyerer and
• Christian Ducho

Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77

• diastereoselectively converted with a Grignard reagent into the amine 53 as a key step of the synthesis [78]. Cbz protection followed by ozonolysis with subsequent reductive amination and hydrogenolysis led to the 1,3-diamine 54. The cyclisation to the guanidine functionality was achieved with the novel

Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• = BPh4 or Cl). Self-assembly of these block copolymers into core–shell spherical micelles was successfully conducted and, by UV/ozonolysis or thermal pyrolysis generating antiferromagnetic CoO species, some of these micelles could be converted into inorganic nanoparticles. With the aim at extending the

Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

• Tatjana Huber,
• Lara Weisheit and
• Thomas Magauer

Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273

• butenolide 140 from (R)-citronellol (139) in an 11-step sequence. Next, the two stereocenters at C2 and C3 position were installed by stereoselective conjugate addition of enantiopure α-allylphosphonamide 141 to butenolide 140. After cleavage of the chiral auxiliary by ozonolysis, aldehyde 142 was protected

• as the dimethoxy acetal and reduction of the lactone followed by olefination furnished alkene 143. The lactone fragment of the natural product was then installed by acidic hydrolysis of the acetal functionality and subsequent oxidation gave γ-lactone 144. Ozonolysis of the terminal alkene and

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• treated with dilithiated 2-methyl-1-butene-3-yne (104) to generate the corresponding bis-enyne 105. Treatment with Pd(PPh3)4 in dry toluene under high dilution conditions at 100 °C afforded the exomethylene paracyclophane 106. The paracyclophane 106 was converted to oxocyclophane 107 by ozonolysis

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

• group and thus separation of the C-2 epimeric mixture prior to the Amadori rearrangement is not necessary. Simple ozonolysis of the diastereomeric mixture 6 afforded a mixture of the protected D-glycero-D-galacto- and D-glycero-D-talo-configured heptoses 7a and 7b in quantitative yield. After sequential

Electrochemical selenium- and iodonium-initiated cyclisation of hydroxy-functionalised 1,4-dienes

• Philipp Röse,
• Steffen Emge,
• Jun-ichi Yoshida and
• Gerhard Hilt

Beilstein J. Org. Chem. 2015, 11, 174–183, doi:10.3762/bjoc.11.18

• reaction has been described where the carbon–carbon bond formation, either at the terminal carbon of the double bond (C1) or on C2 was formed, depending on the ligand system applied [5][6]. Besides the ozonolysis of the 1,4-dienes for the generation of 1,3-dicarbonyl derivatives [7][8][9], these 1,4-dienes

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

• under irradiation of its alcoholic solutions with a mercury lamp in an oxygen atmosphere; esters were obtained in higher yields in the presence of catalytic amounts of HCl [172]. The formation of primary and secondary alcohol esters was observed after the ozonolysis of a mixture of aldehyde and alcohol

The Shono-type electroorganic oxidation of unfunctionalised amides. Carbon–carbon bond formation via electrogenerated N-acyliminium ions

• Alan M. Jones and
• Craig E. Banks

Beilstein J. Org. Chem. 2014, 10, 3056–3072, doi:10.3762/bjoc.10.323

• -acyliminium ion cyclisation strategy in the presence of a disubstituted acetylene nucleophile. Anodic oxidation proceeded in high yield and a smooth cyclisation of the pendant acetylene nucleophile was triggered by treatment with titanium tetrachloride. Ozonolysis of the chloromethyl alkene intermediate

Formal total syntheses of classic natural product target molecules via palladium-catalyzed enantioselective alkylation

• Yiyang Liu,
• Marc Liniger,
• Ryan M. McFadden,
• Jenny L. Roizen,
• Jacquie Malette,
• Corey M. Reeves,
• Douglas C. Behenna,
• Masaki Seto,
• Jimin Kim,
• Justin T. Mohr,
• Scott C. Virgil and
• Brian M. Stoltz

Beilstein J. Org. Chem. 2014, 10, 2501–2512, doi:10.3762/bjoc.10.261

• unprotected piperidinone (+)-47 (made previously in the formal synthesis of (+)-rhazinilam shown in Scheme 11) to produce internal olefin 63 (Scheme 15) [109]. Ozonolysis of the double bond furnished aldehyde 64, which was reduced under Luche conditions to alcohol 65, a compound identical in structure and

Indium-mediated allylation in carbohydrate synthesis: A short and efficient approach towards higher 2-acetamido-2-deoxy sugars

• Christopher Albler,
• Ralph Hollaus,
• Hanspeter Kählig and
• Walther Schmid

Beilstein J. Org. Chem. 2014, 10, 2230–2234, doi:10.3762/bjoc.10.231

• makes use of readily accessible pentoses and hexoses, which are subjected to indium-mediated two-carbon chain elongation. Subsequent ozonolysis and treatment with base yields α,β-unsaturated aldehydes, which are stereoselectively epoxidized using Jørgenson’s protocol. After Wittig chain elongation the

• obtained allylic epoxides were regio- and stereoselectively opened with trimethylsilyl azide under palladium catalysis. Finally, a suitable deprotection protocol, starting with acidic acetate cleavage and ozonolysis was established. Peracetylation of the products simplifies purification and subsequent

• reaction furnished olefins 2a and 2b after acetylation in quantitative yield (Scheme 1). In the gluco-case a yield of 70% for 2c was obtained owing to incomplete consumption of the starting material 1c. Ozonolysis of the olefins 2 was performed using thiourea as reducing agent. Subsequently the generated 2

Relay cross metathesis reactions of vinylphosphonates

• Raj K. Malla,
• Jeremy N. Ridenour and
• Christopher D. Spilling

Beilstein J. Org. Chem. 2014, 10, 1933–1941, doi:10.3762/bjoc.10.201

• via ozonolysis to the aldehyde 6, a known intermediate [17][18] on route to (−)-centrolobine (8). An alternative approach could involve an alkene cross metathesis reaction between the vinylphosphonate and a styrene (5 to 7). Since substituted vinylphosphonates are reluctant to participate in cross

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

• bearing the chiral auxiliary can be cleaved by ozonolysis to the corresponding aldehydes 36 and the latter reduced to alcohols 37, respectively, as shown in Scheme 4. Many highly functionalized, vicinally substituted compounds could be prepared by this method in good to excellent enantiopurity [37][38][39

• phosphorus center, whereas cis confers to a R-configuration. Degradation of the adducts by ozonolysis yielded oxocycloalkane-3-carboxaldehydes 43, which are useful synthetic intermediates. Diastereomer cis-40b however gave only poor diastereofacial selection, providing the corresponding 1,4-addition adducts

• in 28–64% ee [5]. In a similar fashion, Denmark’s oxazaphosphorinane cis-44a yielded keto esters 46a–c in high optical purities via conjugate addition to enones 41 followed by ozonolysis and oxidative esterification. Using diastereomer trans-44b on the other hand provided ketoesters 46a–c with only

Postsynthetic functionalization of glycodendrons at the focal point

• Thisbe K. Lindhorst and
• Katharina Elsner

Beilstein J. Org. Chem. 2014, 10, 1482–1487, doi:10.3762/bjoc.10.152

• divalent glycodendron 3 (Scheme 1). Then, ozonolysis yields the alcohol 4 in a quantitative reaction, which can be further modified at the focal hydroxy group, leading to 5 after allylation and to the primary alcohol 6 in the following ozonolysis step. However, the alcohol 4 can also be employed in another

Structure elucidation of female-specific volatiles released by the parasitoid wasp Trichogramma turkestanica (Hymenoptera: Trichogrammatidae)

• Armin Tröger,
• Teris A. van Beek,
• Martinus E. Huigens,
• Isabel M. M. S. Silva,
• Maarten A. Posthumus and
• Wittko Francke

Beilstein J. Org. Chem. 2014, 10, 767–773, doi:10.3762/bjoc.10.72

• products by enantioselective gas chromatography. However, ozonolysis of a natural sample [29] containing the two compounds, followed by reductive work-up, would yield syn,syn-2,4,6-trimethylnonanol, the enantiomers of which can be easily separated by using heptakis-[2,3-di-O-methyl-6-O-(tert

Phosphinate-containing heterocycles: A mini-review

• Olivier Berger and
• Jean-Luc Montchamp

Beilstein J. Org. Chem. 2014, 10, 732–740, doi:10.3762/bjoc.10.67

• 2 equivalents of cinnamyl alcohol 44 in the presence of 2 mol % of Pd/Xanthpos followed by an esterification using benzyl bromide. Ozonolysis, and reductive amination using excess benzylamine in the presence of sodium cyanoborohydride completed the synthesis. Phosphorines Two phosphorines 47a,b were

Simple two-step synthesis of 2,4-disubstituted pyrroles and 3,5-disubstituted pyrrole-2-carbonitriles from enones

• Murat Kucukdisli,
• Dorota Ferenc,
• Marcel Heinz,
• Christine Wiebe and
• Till Opatz

Beilstein J. Org. Chem. 2014, 10, 466–470, doi:10.3762/bjoc.10.44

• which can be cyclized to compounds 7 in yields of up to 50% (over 4 steps) [42]. Other methods involve the use of stoichiometric zirconocene dichloride [43], the reductive coupling of alkynes to enones followed by ozonolysis and Paal–Knorr cyclization [21] or the reaction of vinylazides with aldehydes

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• ozonolysis to give aldehyde 136 [123]. Knoevenagel condensation with 4-iodooxindole was achieved in the next step. Pfitzner–Moffatt oxidation [124] followed by elimination furnished trans-divinylcycloproane 137. Submission of this compound to elevated temperature initiated a very smooth DVCPR yielding

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

• Alexander O. Terent'ev,
• Dmitry A. Borisov,
• Vera A. Vil’ and
• Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

• Mukaiyama–Isayama peroxysilylation of unsaturated compounds, the Kobayashi cyclization, the nucleophilic addition of hydrogen peroxide to carbonyl compounds, the ozonolysis, and reactions with the involvement of peroxycarbenium ions. Each part of the review deals with a particular class of the above

• )cyclohexyl)propan-2-one) (58) in two steps. The latter was treated with p-TsOH to give the target peroxide 59 (Scheme 18) [252]. 1.3. The use of ozone. Peroxycarbenium ions in the 1,2-dioxolanes synthesis The ozonolysis of unsaturated compounds is a reliable and facile method for the introduction of the

• peroxide functional group. As in the above-considered studies, the intramolecular cyclization of ozonolysis products can be performed with the use of the hydroperoxide group provided that there is an appropriate electrophilic center. The reaction of oxetanes 60a,b with ozone in methanol produced 3-alkoxy

Towards stereochemical control: A short formal enantioselective total synthesis of pumiliotoxins 251D and 237A

• Jie Zhang,
• Hong-Kui Zhang and
• Pei-Qiang Huang

Beilstein J. Org. Chem. 2013, 9, 2358–2366, doi:10.3762/bjoc.9.271

• consisting of ozonolysis and reductive dehydroxylation provided the indolizidine derivative 5, which completed the formal enantioselective total synthesis of pumiliotoxins 251D and 237A. Keywords: enantioselective synthesis; Grignard reagent; pumiliotoxin 237A; pumiliotoxin 251D; reductive dehydroxylation

• form the indolizidinone ring. Thus, ozonolysis of olefin 22 in dichloromethane [51], followed by quenching with Me2S furnished the hemiaminal tautomer via intermediacy of lactam-aldehyde. Without isolation, the crude was subjected to the reductive dehydroxylation with Et3SiH/BF3·Et2O (CH2Cl2, −78 °C

The chemistry of isoindole natural products

• Klaus Speck and
• Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

• ozonolysis and acid-promoted cyclization afforded (+)-41 and (−)-41 in an overall yield of 60% and 46%, respectively. For the synthesis of staurosporinone (30) and its 3,4-dimethoxybenzyl (DMB)-protected derivative 45, a ruthenium-catalyzed C–H insertion/electrocyclization cascade using 2,2’-bisindole 44 and

The preparation of several 1,2,3,4,5-functionalized cyclopentane derivatives

• André S. Kelch,
• Peter G. Jones,
• Ina Dix and
• Henning Hopf

Beilstein J. Org. Chem. 2013, 9, 1705–1712, doi:10.3762/bjoc.9.195

• excellent yield [7]. This bicyclic adduct was converted by ozonolysis followed by LAH reduction into the all-cis-derivative 15, whose benzyl ether protection group was finally removed by catalytic hydrogenation over palladium on carbon [7][8]. The full experimental details and the complete set of the

A reductive coupling strategy towards ripostatin A

• Kristin D. Schleicher and
• Timothy F. Jamison

Beilstein J. Org. Chem. 2013, 9, 1533–1550, doi:10.3762/bjoc.9.175

• . Ozonolysis of the pendant olefin afforded aldehyde 75 in high yield. Following the prior procedure, the lithium enolate of TMS ester 64 was reacted with aldehyde 75, and the mixture of diastereomeric alcohols was oxidized to the β-ketoester 76 (Scheme 20). This substrate did not appear to be prone to

Re₂O₇-catalyzed reaction of hemiacetals and aldehydes with O-, S-, and C-nucleophiles

• Wantanee Sittiwong,
• Michael W. Richardson,
• Charles E. Schiaffo,
• Thomas J. Fisher and
• Patrick H. Dussault

Beilstein J. Org. Chem. 2013, 9, 1526–1532, doi:10.3762/bjoc.9.174

• were curious about the interactions of Re(VII) oxides with hydroperoxyacetals (1-alkoxyhydroperoxides), versatile intermediates available from ozonolysis of alkenes in alcoholic solvents [23][24]. As can be seen in Table 8, Re2O7, Me3SiOReO3 and PTSA all catalyze alkoxide metathesis to furnish a

• lack of reactivity of ozonolysis-derived 1-methoxyhydroperoxides towards methanolic acid may mask a rapid degenerate exchange [27]. The failure of the perrhenate to catalyze formation of N,O-acetals was initially perplexing. However, reported perrhenate-promoted dehydrations of amides and oximes