Preparation of renieramycin left-half model compounds

Nakai, Keiyo; Kubo, Kōji; Yokoya, Masashi; Saito, Naoki

doi:10.1016/j.tet.2014.07.012

Cited by 16 publications

(23 citation statements)

References 18 publications

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“…According to the results of our previous studies [ 21 , 22 ], treatment of 8 with trimethylsilyl chloride (TMSCl) in the presence of triethylamine (TEA) in CH 2 Cl 2 gave O -trimethylsilyl lactim intermediate 14 , which was treated with 2,2-diethoxyethyl benzoate in the presence of trimethylsilyl triflate (TMSOTf) and acetic anhydride to give 15 as an inseparable mixture of diastereomers ( 15a : 15b = 10:3) in 92% yield. After exerting a great deal of effort to separate this mixture by column chromatography several times, we obtained both isomers in their pure forms, and detailed 2D NMR studies confirmed the structures of 15a (minor) and 15b (major).…”

Section: Resultsmentioning

confidence: 99%

Chemistry of Renieramycins. Part 14: Total Synthesis of Renieramycin I and Practical Synthesis of Cribrostatin 4 (Renieramycin H)

et al. 2015

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The first total synthesis of (±)-renieramycin I, which was isolated from the Indian bright blue sponge Haliclona cribricutis, is described. The key step is the selenium oxide oxidation of pentacyclic bis-p-quinone derivative (3) stereo- and regioselectively. We also report a large-scale synthesis of cribrostatin 4 (renieramycin H) via the C3-C4 double bond formation in an early stage based on the Avendaño’s protocol, from readily available 1-acetyl-3-(3-methyl-2,4,5-trimethylphenyl)methyl-piperazine-2,5-dione (8) in 18 steps (8.3% overall yield). The synthesis provides unambiguous evidence supporting the original structure of renieramycin I.

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Section: Resultsmentioning

confidence: 99%

Chemistry of Renieramycins. Part 14: Total Synthesis of Renieramycin I and Practical Synthesis of Cribrostatin 4 (Renieramycin H)

et al. 2015

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“…Pictet-Spengler reaction in total synthesis of natural products. [103,104] (+)-yohimbine Figure 3 Reported in [65] - [105] (−)-corynantheidine Figure 3 Reported in [65] corynanthe alkaloids [106] (−)-corynantheine (−)-dihydrocorynantheine Figure 3 Reported in [65] corynanthe alkaloids [107] (−)-affinisine oxindole Figure 3 Reported in [66] - [108] (2011) Cyclization of 3-arylidene-6-methylpiperazinedione 75 with 2,2-diethoxyethyl benzoate afforded in two steps the P-S-adduct 76 as a single isomer (Scheme 21). The lactam 76 was used to construct the pentacyclic key intermediate framework (not shown) [82] and achieve the total synthesis of cribrostatin 4 [83] and renieramycin G ( Figure 3) [84,85].…”

Section: Polyheterocyclesmentioning

confidence: 99%

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confidence: 99%

“…(2014-2015) Saito and coworkers presented an alternative large-scale approach for the total synthesis of cribrostatin four analogs, as well as C3-C4 unsaturated bis-p-quinone derivatives, such as renieramycin I. According to the results of previous studies [103], the treatment of the readily available compound 98 with trimethylsilyl chloride (TMSCl) in DCM in the presence of triethylamine afforded lactam intermediate 99, which, in turn, treated with 2,2-diethoxyethyl benzoate in the presence of trimethylsilyl triflate (TMSOTf) and Ac 2 O gave the P-S product 100 as a diastereomeric mixture (a/b: 10/3) in 92% yield (Scheme 28) [104]. The conversion of the diketopiperazine THIQ 100 into unsaturated compound 101 was the first key step of the synthesis of renieramycin I and cribrostatin 4 (Figure 3) (2011) The P-S reaction got a lead role in the total syntheses of (+)-yohimbine [105], (−)corynantheidine [106,107], (+)-corynantheine, and (+)-dihydrocorynantheine [107] (active as antimicrobial against Staphylococcus aureus-induced infections [109]), which have been reviewed in Todd's paper [65].…”

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confidence: 99%

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The Pictet-Spengler Reaction Updates Its Habits

et al. 2020

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The Pictet-Spengler reaction (P-S) is one of the most direct, efficient, and variable synthetic method for the construction of privileged pharmacophores such as tetrahydro-isoquinolines (THIQs), tetrahydro-β-carbolines (THBCs), and polyheterocyclic frameworks. In the lustro (five-year period) following its centenary birthday, the P-S reaction did not exit the stage but it came up again on limelight with new features. This review focuses on the interesting results achieved in this period (2011–2015), analyzing the versatility of this reaction. Classic P-S was reported in the total synthesis of complex alkaloids, in combination with chiral catalysts as well as for the generation of libraries of compounds in medicinal chemistry. The P-S has been used also in tandem reactions, with the sequences including ring closing metathesis, isomerization, Michael addition, and Gold- or Brønsted acid-catalyzed N-acyliminium cyclization. Moreover, the combination of P-S reaction with Ugi multicomponent reaction has been exploited for the construction of highly complex polycyclic architectures in few steps and high yields. The P-S reaction has also been successfully employed in solid-phase synthesis, affording products with different structures, including peptidomimetics, synthetic heterocycles, and natural compounds. Finally, the enzymatic version of P-S has been reported for biosynthesis, biotransformations, and bioconjugations.

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“…Besides, the topological configuration and the length of the molecular skeleton are thought to have great influence on their interaction with DNA and other biomacromolecules [1]. Indeed, studies show that the decrease of cytotoxic activities of the bistetrahydroisoquinoline analogues may be attributed to the changes of topological configuration and the length of the molecular skeleton [9][10][11].…”

Section: Introductionmentioning

confidence: 99%