Asymmetric synthesis of a stereopentade fragment toward latrunculins

• Benjamin Joyeux,
• Antoine Gamet,
• Nicolas Casaretto and
• Bastien Nay

Beilstein J. Org. Chem. 2023, 19, 428–433, doi:10.3762/bjoc.19.32

• stereoselectivity. Starting from the chiral pool bringing the 8-methyl substituent, the secondary alcohol on C-11 was stereoselectively introduced by the Krische allylation of alcohol 11. The next key step consisted in an aldol reaction of ketone 15 onto aldehyde 8, which proceeded with a high stereocontrol

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

• Cécile Alleman,
• Charlène Gadais,
• Laurent Legentil and
• François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

Vicinal ketoesters – key intermediates in the total synthesis of natural products

• Marc Paul Beller and
• Ulrich Koert

Beilstein J. Org. Chem. 2022, 18, 1236–1248, doi:10.3762/bjoc.18.129

• species to the α-ketoester 15 (Scheme 3) [6]. The ketoester 15 was synthesized by a chiral pool approach starting from (+)-3-carene derived cycloheptenone 13 [7][8] and aldehyde 12 (accessible from (R)-Roche ester [9]) via the γ-lactone 14. The ketoester moiety was established by an enolate hydroxylation

Synthesis and late stage modifications of Cyl derivatives

• Phil Servatius and
• Uli Kazmaier

Beilstein J. Org. Chem. 2022, 18, 174–181, doi:10.3762/bjoc.18.19

• degree of variability for the generation of small libraries, in our case of Cyl-1 derivatives. Chiral allylic alcohols are easily accessible, either via kinetic resolution of racemic alcohols [46][47], asymmetric catalysis [48], or from chiral pool materials, such as threitol 1 [49]. Using the last

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• be accessed from the chiral pool. Both types of organocatalysts, namely those acting through non-covalent bonding as well as those working by making covalent bonding have been employed for accomplishing asymmetric aza-MRs. There are several review articles available on organocatalytic asymmetric aza

Syntheses of spliceostatins and thailanstatins: a review

• William A. Donaldson

Beilstein J. Org. Chem. 2020, 16, 1991–2006, doi:10.3762/bjoc.16.166

• Syntheses from ʟ-threonine-derived aldehyde Three groups utilized 4-formyl-2,2,5-trimethyl-3-oxazolidine (24) [21], derived from relatively inexpensive ʟ-threonine (<$1/g in bulk) as a chiral pool precursor for the amine stereocenter of the (all-cis)-2,3,5,6-tetrasubstituted tetrahydropyran fragment. In

• FR901464 (1) from chiral pool precursors Kitahara’s group fashioned the C-1–C-6 tetrahydropyran fragment of FR901464 (1) from commercially available 2-deoxy-ᴅ-glucose. In the first-generation approach (66, Scheme 10) [8], a sequence of protection and oxidation steps generated the tetrahydropyrone 67 at

• product, this route is shorter and higher-yielding (11 steps, 11.5%) than the Kitahara synthesis. However, it suffers from repeated protection/deprotection steps. The Ghosh group utilized (R)-glyceraldehyde acetonide (79, readily available from ᴅ-mannitol) as a chiral pool precursor for the introduction

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

• efficiency of a 2-substituted N-(1-phenylethyl)aziridine framework as chiron bearing a chiral auxiliary. Keywords: alkaloids; amino acids; asymmetric synthesis; ceramides; chiral catalysis; chiral pool; N-(1-phenylethyl)aziridine chiron; sphingoids; Introduction The synthesis of enantiomerically pure

Alkylation of lithiated dimethyl tartrate acetonide with unactivated alkyl halides and application to an asymmetric synthesis of the 2,8-dioxabicyclo[3.2.1]octane core of squalestatins/zaragozic acids

• Herman O. Sintim,
• Hamad H. Al Mamari,
• Hasanain A. A. Almohseni,
• Younes Fegheh-Hassanpour and
• David M. Hodgson

Beilstein J. Org. Chem. 2019, 15, 1194–1202, doi:10.3762/bjoc.15.116

• (≈80:20 dr) with reactive organohalides (Scheme 4) [17]. The process was valuable, because it allowed direct elaboration of a chiral pool building block that was readily available as either antipode [22][23], with the major alkylated diastereomer 15 being generated in 97:3 er [18]. The study was also

A chemoenzymatic synthesis of ceramide trafficking inhibitor HPA-12

• Seema V. Kanojia,
• Sucheta Chatterjee,
• Subrata Chattopadhyay and
• Dibakar Goswami

Beilstein J. Org. Chem. 2019, 15, 490–496, doi:10.3762/bjoc.15.42

• (1R,3S)-HPA-12 (2) used the chiral pool approach [15][16], crystallization-induced asymmetric transformation [17], diastereoselective reduction of γ-aryl-γ-oxo-β-amino alcohol [18], cycloaddition of oxime with alkenes [19], enantioselective carbonyl reduction followed by an organocatalyzed α-amination

Synthesis of nonracemic hydroxyglutamic acids

• Dorota G. Piotrowska,
• Iwona E. Głowacka,
• Andrzej E. Wróblewski and
• Liwia Lubowiecka

Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22

• pyroglutamic acids, proline and 4-hydroxyproline). Since various hydroxyglutamic acids were identified as components of complex natural products, syntheses of orthogonally protected derivatives of hydroxyglutamic acids are also covered. Keywords: amino acids; asymmetric synthesis; chiral catalysis; chiral

• pool; glutamate analogues; Introduction L-Glutamic acid (1, Figure 1) plays an important role in the biosynthesis of purine and pyrimidine nucleobases [1]. It also takes part in metabolic transformation to L-glutamine by L-glutamate synthetase (GS) which is crucial for cell maintenance. In neoplastic

Stereodivergent approach in the protected glycal synthesis of L-vancosamine, L-saccharosamine, L-daunosamine and L-ristosamine involving a ring-closing metathesis step

• Pierre-Antoine Nocquet,
• Aurélie Macé,
• Frédéric Legros,
• Jacques Lebreton,
• Gilles Dujardin,
• Sylvain Collet,
• Arnaud Martel,
• Bertrand Carboni and
• François Carreaux

Beilstein J. Org. Chem. 2018, 14, 2949–2955, doi:10.3762/bjoc.14.274

• was obtained in similar yield than one reported [8][47]. Synthesis of daunosamine and ristosamine glycals. As previously, the chiral pool material 5 was used for this unbranched glycal synthesis (Scheme 4). The first step was the chelation-controlled addition of allylmagnesium bromide to 5 to provide

Synthesis of 2-aminosuberic acid derivatives as components of some histone deacetylase inhibiting cyclic tetrapeptides

• Shital Kumar Chattopadhyay,
• Suman Sil and
• Jyoti Prasad Mukherjee

Beilstein J. Org. Chem. 2017, 13, 2153–2156, doi:10.3762/bjoc.13.214

• and the synthesis of peptides of biological relevance. Keywords: α-amino acid; catalysis; chiral pool; cross metathesis; cyclic peptides; Introduction α-Aminosuberic acid (Asu) is a component of apicidin F (1, Figure 1) belonging to an interesting class of cyclic tetrapeptides displaying

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

Effect of uridine protecting groups on the diastereoselectivity of uridine-derived aldehyde 5’-alkynylation

• Raja Ben Othman,
• Mickaël J. Fer,
• Laurent Le Corre,
• Sandrine Calvet-Vitale and
• Christine Gravier-Pelletier

Beilstein J. Org. Chem. 2017, 13, 1533–1541, doi:10.3762/bjoc.13.153

• numerous approaches, this 5′ stereogenic center comes from the chiral pool and the nucleobase is introduced under Vorbrüggen conditions [20][21][22][23][24][25][26]. It can also be created directly on the nucleoside, either by functionalization of an alkene at C-5’ [27][28][29][30][31][32] or by the

Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

• M. Fernanda N. N. Carvalho,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2017, 13, 1230–1238, doi:10.3762/bjoc.13.122

• ; platinum; Introduction Enantiomerically pure raw materials, available in a sustainable manner from the natural “chiral pool” [1], offer a convenient entrance for the chemical synthesis of other chiral compounds, e.g., rare natural products and their analogues [2], or chiral catalysts [3][4]. A prominent

• example for such a “chiral pool” starting material is camphor. Both its substituents and its bicyclic skeleton can easily be modified and adapted to the purpose at hand, e.g., natural product synthesis [5]. The Wagner–Meerwein and Nametkin-type rearrangements are the most common reaction patterns [6] and

Synthesis of new pyrrolidine-based organocatalysts and study of their use in the asymmetric Michael addition of aldehydes to nitroolefins

• Alejandro Castán,
• Ramón Badorrey,
• José A. Gálvez and
• María D. Díaz-de-Villegas

Beilstein J. Org. Chem. 2017, 13, 612–619, doi:10.3762/bjoc.13.59

• tuneable catalytic motifs to be used in organocatalysis starting from the chiral pool. Highly modular chiral aminodiol derivatives were obtained by the addition of organometallic reagents to chiral imines derived from (R)-glyceraldehyde – which is easily accessible from D-mannitol – and these were

• chiral pool, we have now focused on the synthesis of new chiral pyrrolidines capable of creating a sterically demanding environment due to the presence of a bulky 2,2-disubstituted-1,3-dioxolan-4-yl moiety at C2 from chiral imines derived from (R)-glyceraldehyde. The Michael addition of aldehydes to

• be obtained on a multigram scale from the chiral pool. In order to obtain a series of new organocatalysts with substituents of different sizes and stereoelectronic properties in the dioxolane moiety, the following reaction sequence was applied to compounds 2 and 4: a) N-deprotection by hydrogenolysis

Spiro-fused carbohydrate oxazoline ligands: Synthesis and application as enantio-discrimination agents in asymmetric allylic alkylation

• Jochen Kraft,
• Martin Golkowski and
• Thomas Ziegler

Beilstein J. Org. Chem. 2016, 12, 166–171, doi:10.3762/bjoc.12.18

• building blocks for pharmaceuticals, agrochemicals or flavors. Carbohydrates are inexpensive and easy to obtain enantiomerically pure natural products and therefore, nearly ideal starting materials for ex-chiral pool syntheses. In addition, carbohydrates have significantly gained attention as ligands for

Stereoselective cathodic synthesis of 8-substituted (1R,3R,4S)-menthylamines

• Carolin Edinger,
• Jörn Kulisch and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2015, 11, 294–301, doi:10.3762/bjoc.11.34

• fraction of starting materials for the synthesis of these compounds is still provided by the chiral pool. Usually, optically active alcohols or amino acids serve as starting material for such amine syntheses [14]. Naturally occurring terpenes such as carene [15], limonene [16], pinene [17][18] or camphor

Enantioselective synthesis of polyhydroxyindolizidinone and quinolizidinone derivatives from a common precursor

• Nemai Saha and
• Shital K. Chattopadhyay

Beilstein J. Org. Chem. 2014, 10, 3104–3110, doi:10.3762/bjoc.10.327

• from a common intermediate which featured a highly selective dihydroxylation reaction and a RCM reaction as key steps. Keywords: chiral pool; dihydroxylation; indolizidines; quinolizidine; ring-closing metathesis; Introduction Polyhydroxylated indolizidine derivatives have attracted continued

Amino acid motifs in natural products: synthesis of O-acylated derivatives of (2S,3S)-3-hydroxyleucine

• Oliver Ries,
• Martin Büschleb,
• Markus Granitzka,
• Dietmar Stalke and
• Christian Ducho

Beilstein J. Org. Chem. 2014, 10, 1135–1142, doi:10.3762/bjoc.10.113

• opening up an excellent approach for the synthesis of bioactive natural products and derivatives thereof for structure activity relationship (SAR) studies. Keywords: chiral pool; cross metathesis; esterification; β-hydroxy-α-amino acids; natural products; Introduction Besides the proteinogenic β-hydroxy

• protecting group pattern. The most promising strategy to achieve these goals appeared to be a variation of the ex-chiral pool synthesis developed by Zhu and co-workers [32]. They have utilized the stereocenter of D-serine in a diastereoselective Grignard addition to protected D-serinal as the key step of

Synthesis of (2S,3R)-3-amino-2-hydroxydecanoic acid and its enantiomer: a non-proteinogenic amino acid segment of the linear pentapeptide microginin

• Rajendra S. Rohokale and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2014, 10, 667–671, doi:10.3762/bjoc.10.59

• multicomponent condensation reactions of aldehyde, an amine and ketene silyl acetal derivatives to get the vicinal hydroxylamino acids [17]. In addition, a few strategies employ a chiral pool approach. For example, Wee et al. utilized the zinc-silver-mediated reductive elimination of α-D-lyxofuranosyl

Synthesis of new enantiopure poly(hydroxy)aminooxepanes as building blocks for multivalent carbohydrate mimetics

• Léa Bouché,
• Maja Kandziora and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 213–223, doi:10.3762/bjoc.10.17

• ]. The general approach is shown in Scheme 1: the chiral pool-derived nitrones A [29][30] undergo a [3 + 3]-cyclization with lithiated [2-(trimethylsilyl)ethoxy]allene (TMSE-allene) [31] as C-3 building block [32] to form the 3,6-dihydro-2H-1,2-oxazines B; subsequent Lewis acid-promoted reactions [23

Novel supramolecular affinity materials based on (−)-isosteviol as molecular templates

• Christina Lohoelter,
• Malte Brutschy,
• Daniel Lubczyk and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2013, 9, 2821–2833, doi:10.3762/bjoc.9.317

• Christina Lohoelter Malte Brutschy Daniel Lubczyk Siegfried R. Waldvogel Institute for Organic Chemistry, Johannes Gutenberg University, Duesbergweg 10–14, 55128 Mainz, Germany 10.3762/bjoc.9.317 Abstract The readily available ex-chiral-pool building block (−)-isosteviol was combined with the C3

Stereodivergent synthesis of jaspine B and its isomers using a carbohydrate-derived alkoxyallene as C₃-building block

• Volker M. Schmiedel,
• Stefano Stefani and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2013, 9, 2564–2569, doi:10.3762/bjoc.9.291

• than 30 published syntheses up to now. Most frequently they are based on transformations of starting materials available from the ”chiral pool”, e.g. L-serine [7][8][9][10][11][12][13][14][15][16][17][18], or by asymmetric catalysis [19][20][21][22][23][24][25]. Several publications also focused on the

Bidirectional cross metathesis and ring-closing metathesis/ring opening of a C₂-symmetric building block: a strategy for the synthesis of decanolide natural products

• Bernd Schmidt and
• Oliver Kunz

Beilstein J. Org. Chem. 2013, 9, 2544–2555, doi:10.3762/bjoc.9.289

• Bernd Schmidt Oliver Kunz Institut für Chemie, Organische Synthesechemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam-Golm, Germany 10.3762/bjoc.9.289 Abstract Starting from the conveniently available ex-chiral pool building block (R,R)-hexa-1,5-diene-3,4-diol, the ten

• structure elucidation and for correcting erroneous assignments. In particular if ex-chiral pool starting materials with well established absolute configurations are used, such as D-mannitol-derived 1 or L-tartrate-derived ent-1, highly reliable structural assignments become possible. Two decanolides, for

• ° in the case of the diastereomeric epoxide 39b, and this value fits well to the observed 3J(H5–H6) value (Figure 2) [65]. Conclusion In summary, we synthesized the naturally occurring ten-membered lactones stagonolide E and curvulide A, starting from the ex-chiral pool building block (R,R)-hexa-1,5