Enantioselective synthesis of β-aryl-γ-lactam derivatives via Heck–Matsuda desymmetrization of N-protected 2,5-dihydro-1H-pyrroles

• Arnaldo G. de Oliveira Jr.,
• Martí F. Wang,
• Rafaela C. Carmona,
• Danilo M. Lustosa,
• Sergei A. Gorbatov and
• Carlos R. D. Correia

Beilstein J. Org. Chem. 2024, 20, 940–949, doi:10.3762/bjoc.20.84

• followed by a sequential Jones oxidation. The overall method displays a broad scope and good enantioselectivity, favoring the (R) enantiomer. The applicability of the protocol is highlighted by the efficient enantioselective syntheses of the selective phosphodiesterase-4-inhibitor rolipram and the

• Heck adducts (methyl N,O-acetals) were efficiently converted into several arylated γ-lactams by a simple oxidation procedure (Jones oxidation). To demonstrate the applicability of the strategy, two of the chiral aryl-lactams were further derivatized to provide the selective phosphodiesterase-4

• presence of a methoxy group after the Heck–Matsuda reaction indicates methanolysis after arylation. Given the importance of the lactam rings, we envisioned a sequential Jones oxidation protocol without isolation of the methyl N,O-acetal products to obtain the corresponding lactams 4. As observed in

Honeycomb reactor: a promising device for streamlining aerobic oxidation under continuous-flow conditions

• Masahiro Hosoya,
• Yusuke Saito and
• Yousuke Horiuchi

Beilstein J. Org. Chem. 2023, 19, 752–763, doi:10.3762/bjoc.19.55

• closed system. Keywords: aerobic oxidation; benzaldehydes; benzyl alcohols; homogeneous catalyst; honeycomb reactor; Introduction Oxidation plays a key role in synthesizing highly functionalized molecules [1][2]. While Jones oxidation [3] and oxidation using KMnO4 [4] are classical and powerful methods

Total synthesis of grayanane natural products

• Nicolas Fay,
• Rémi Blieck,
• Cyrille Kouklovsky and
• Aurélien de la Torre

Beilstein J. Org. Chem. 2022, 18, 1707–1719, doi:10.3762/bjoc.18.181

• hydrolysis, esterification, and Jones oxidation, affording intermediate 14 with a good 79% yield over 4 steps. Next, the methyl ketone was converted to an enol triflate, and then coupled with Li2CuCN(CH2SPh)2. A reduction of the ester with DIBAL, followed by Dess–Martin oxidation and Wittig reaction lead to

N-Acylated amino acid methyl esters from marine Roseobacter group bacteria

• Hilke Bruns,
• Lisa Ziesche,
• Nargis Khakin Taniwal,
• Laura Wolter,
• Thorsten Brinkhoff,
• Jennifer Herrmann,
• Rolf Müller and
• Stefan Schulz

Beilstein J. Org. Chem. 2018, 14, 2964–2973, doi:10.3762/bjoc.14.276

• synthesized as shown in Scheme 1 to verify the structural proposal. 11-Bromoundecan-1-ol (3) was converted into the alcohol 13-methyltetradecan-1-ol (4) with isobutylmagnesium bromide under Li2CuCl4 catalysis according to Mori et al. [28]. After Jones oxidation, 13-methyltetradecanoic acid (5) was coupled

The use of 4,4,4-trifluorothreonine to stabilize extended peptide structures and mimic β-strands

• Yaochun Xu,
• Isabelle Correia,
• Tap Ha-Duong,
• Nadjib Kihal,
• Jean-Louis Soulier,
• Julia Kaffy,
• Benoît Crousse,
• Olivier Lequin and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2017, 13, 2842–2853, doi:10.3762/bjoc.13.276

• separated at this stage by column chromatography. The major diastereomer 7a was used in the following steps. Hydrolysis of the oxazolidine, followed by Jones oxidation of the alcohol 8, allowed us to recover the desired acid 9 in good yield (90%). The optical rotation of a solution of the product 9 (2S,3R

Recent progress in the racemic and enantioselective synthesis of monofluoroalkene-based dipeptide isosteres

• Myriam Drouin and
• Jean-François Paquin

Beilstein J. Org. Chem. 2017, 13, 2637–2658, doi:10.3762/bjoc.13.262

• 11 was converted into the trichloroimidate, and heating in xylenes permitted a [3,3]-sigmatropic rearrangement. At this stage, the trichloroimidate was transformed into an NHBoc moiety. Deprotection of the alcohol followed by Jones oxidation gave the final dipeptide isostere 13. Taguchi and co

• the resulting amine 18, cleavage of the alcohol protecting group, Jones oxidation and formation of the methyl ester afforded the corresponding dipeptide isostere Boc-Ser(PMB)-ψ[(Z)-CF=CH]-Gly-OMe (19). In the same way, Boc-Val-ψ[(Z)-CF=CH]-Gly-OMe, Boc-Leu-ψ[(Z)-CF=CH]-Gly-OMe and Boc-Ala-ψ[(Z)-CF=CH

• Jones oxidation to give the final dipeptide isostere 30. Analogues in which the side chain stereochemistry is controlled Gly-ψ[CF=CH]-Xaa Different strategies have been used over the years to access Gly-ψ[CF=CH]-Xaa isosteres in which the side chain stereochemistry of the Xaa is controlled. This could

Synthesis of polyhydroxylated decalins via two consecutive one-pot reactions: 1,4-addition/aldol reaction followed by RCM/syn-dihydroxylation

• Michał Malik and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2016, 12, 2602–2608, doi:10.3762/bjoc.12.255

• initiated from known iododerivatives 13 and 14, prepared from suitably protected carbohydrates (Scheme 3) [45][46][47]. Each of these compounds was subjected to the zinc-mediated fragmentation, followed by the Jones oxidation. The resulting acid (not purified) was transformed into a Weinreb amide. As a

Synthesis of a deuterated probe for the confocal Raman microscopy imaging of squalenoyl nanomedicines

• Eric Buchy,
• Branko Vukosavljevic,
• Maike Windbergs,
• Dunja Sobot,
• Camille Dejean,
• Simona Mura,
• Patrick Couvreur and
• Didier Desmaële

Beilstein J. Org. Chem. 2016, 12, 1127–1135, doi:10.3762/bjoc.12.109

• directly the alcohol 28 in 41% yield through concomitant reduction of the intermediate allylic chloride and cleavage of the silyl protecting group. The reductive cleavage of tert-butyldiphenylsilyl ethers by LiAlH4 has been previously noticed [39]. Jones oxidation straightforwardly completed the synthesis

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

• alcohol was converted to the corresponding silyl ether. Next, alkylation of the metalated sulfone with allylic chloride 51 afforded alcohol 52 after desilylation. Subsequent desulfonylation with sodium amalgam and Jones oxidation of the primary alcohol furnished carboxylic acid 53. The corresponding

Stereoselective synthesis of hernandulcin, peroxylippidulcine A, lippidulcines A, B and C and taste evaluation

• Marco G. Rigamonti and
• Francesco G. Gatti

Beilstein J. Org. Chem. 2015, 11, 2117–2124, doi:10.3762/bjoc.11.228

• ) stereogenic center by means of a Mitsunobu reaction, followed by transesterification of the ester to give 4 (Scheme 1). (S)-Isopulegone was prepared by Jones oxidation of (−)-isopulegol following a reported procedure [14]; but on a large scale we have observed that a partial loss of the optical purity of the

Recent applications of ring-rearrangement metathesis in organic synthesis

• Sambasivarao Kotha,
• Milind Meshram,
• Priti Khedkar,
• Shaibal Banerjee and
• Deepak Deodhar

Beilstein J. Org. Chem. 2015, 11, 1833–1864, doi:10.3762/bjoc.11.199

• starting material in the synthetic sequence and it was transformed into enone 194 by treatment of vinyl Grignard 106 followed by Jones oxidation. Later, enone 194 was subjected to a DA reaction in the presence of cyclopentadiene (111) to deliver an inseparable mixture of cycloadducts 195 (endo,endo) and

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

• , which was then converted into bromide 75. Debromination and cleavage of the TBDPS protecting group gave protected amino-alcohol 76. Finally, Jones oxidation and removal of the N-Boc protecting group produced crystalline (E)-polyoximic acid (E-9), whose structure was unambiguously confirmed by X-ray

Synthesis and bioactivity of analogues of the marine antibiotic tropodithietic acid

• Patrick Rabe,
• Tim A. Klapschinski,
• Nelson L. Brock,
• Christian A. Citron,
• Paul D’Alvise,
• Lone Gram and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2014, 10, 1796–1801, doi:10.3762/bjoc.10.188

• with tert-butyl acetate (15) and LDA to yield the aldol product 16 that was subsequently oxidised to the β-keto ester 17 in a Jones oxidation. Treatment of the latter with TMSCl, imidazole and DMAP resulted in 18 as a 3:2 mixture of two diastereomers that proved to be unstable. However, the crude

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

• 1.119, which is first alkylated with epichlorohydrin (1.20) [63] (Scheme 22). The resulting epoxide 1.121 can then be ring opened with methanol in the presence of a tin Lewis acid yielding alcohol 1.122, which when subjected to Jones-oxidation conditions and Raney-Ni-mediated hydrogenation furnishes in

Synthesis of the tetracyclic core of Illicium sesquiterpenes using an organocatalyzed asymmetric Robinson annulation

• Lynnie Trzoss,
• Jing Xu,
• Michelle H. Lacoske and
• Emmanuel A. Theodorakis

Beilstein J. Org. Chem. 2013, 9, 1135–1140, doi:10.3762/bjoc.9.126

• this intermediate to Jones oxidation triggered a highly efficient oxidation–epoxide opening [93][94][95][96][97][98] reaction cascade [99][100] to construct the critical D-ring of 9 (46% yield, over 3 steps). Notably, this scalable approach rendered us several hundred milligrams of compound 9, paving

Total synthesis of (±)-coerulescine and (±)-horsfiline

• Mukund G. Kulkarni,
• Attrimuni P. Dhondge,
• Sanjay W. Chavhan,
• Ajit S. Borhade,
• Yunnus B. Shaikh,
• Deekshaputra R. Birhade,
• Mayur P. Desai and
• Nagorao R. Dhatrak

Beilstein J. Org. Chem. 2010, 6, 876–879, doi:10.3762/bjoc.6.103

• rearrangement protocol was applied to obtain 3-allyl oxindole. This oxindole was then converted to (±)-coerulescine and (±)-horsfiline. Keywords: alkaloids; Claisen rearrangement; Jones oxidation; spiro-oxindole; Wittig olefination; Introduction The spiro[pyrrolidin-3,3′-oxindole] ring system is a widely

• allyl vinyl ethers was heated in refluxing xylene to effect the Claisen rearrangement to obtain 4-pentenal 6 in 85% yield. Aldehyde 6 was transformed into acid 7 by Jones oxidation, which was immediately converted to the ethyl ester 8. Subsequently, reduction of the compound 8 with Zn and NH4Cl resulted