Synthesis of the C1–C12 Fragment of Calyculin C

Konstantinova, Olga V.; Koskinen, Ari M. P.

doi:10.1055/s-0037-1610387

Cited by 6 publications

(3 citation statements)

References 43 publications

(43 reference statements)

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“…Protection of the β ‐hydroxyl group of 8 with TBSOTf gave compound 9 in a manner of moderate yield and obvious racemization (Table 1, entry 1). [ 22‐24 ] The TMSOTf/R 3 N combination is also not suitable for the protection the β ‐hydroxyl of 8 due to the reported crossed aldehyde‐aldehyde coupling reactions, enolization, and dehydration of aldehydes containing α‐hydrogen. [ 25‐26 ] At such a circumstance, 8a thus served as the model to explore the conditions for the protection of the β ‐hydroxyl group of 8 .…”

Section: Resultsmentioning

confidence: 99%

Concise Total Synthesis of Dysoxylactam A and a Simplified Analog

et al. 2022

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Comprehensive Summary A total synthesis of 17‐membered macrocyclolipopeptide dysoxylactam A, a potent agent reversing P‐glycoprotein (P‐gp)‐mediated multidrug resistance (MDR) in cancer cells, was developed from the starting material (S)‐2‐methylbutanal in a linear sequence of 12 steps with 23.2% overall yield. The key steps include proline‐catalyzed asymmetric aldol reaction, Evans aldol reaction and Krische allylation to construct the multiple stereocenters containing fragment, and ring‐closing metathesis to furnish the macrocycle. This total synthesis facilitates the preparation of large amount samples of dysoxylactam A and the side chain simplified derivatives for further biological tests and preliminary structure‐activity relationship exploration.

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Section: Resultsmentioning

confidence: 99%

Concise Total Synthesis of Dysoxylactam A and a Simplified Analog

et al. 2022

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“…Fascinatingly, Koskinen and co‐workers presented the synthesis of the C1–C12 fragment 906 (Scheme 142) of calyculin C in a sequence of 10 steps. Calyculin C is a cytotoxic metabolite produced by marine sponge Discodermia calyx [323] . In this synthetic approach, CM was utilized to forge compound 904 in the final steps.…”

Section: Cross Metathesis (Cm)mentioning

confidence: 99%

“…Calyculin C is a cytotoxic metabolite produced by marine sponge Discodermia calyx. [323] In this synthetic approach, CM was utilized to forge compound 904 in the final steps. The Wittig methylation of an aldehyde 901 with Ph 3 PCH 3 I furnished a triene 902, which upon CM with vinyldioxaborolane 903 in the presence of HG-I catalyst provided the compound 904 in reasonable yield.…”

Section: Studies Towards Fragment Syntheses Of Natural Products Based...mentioning

confidence: 99%

Metathesis Reactions in Natural Product Fragments and Total Syntheses

et al. 2022

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The passion of total‐ and fragments syntheses of natural products always remained one of the top priorities among the synthetic chemists worldwide. Due their curiosity toward the complexity of molecules of living nature and their endeavour to imitate them in laboratory; limitless arrays of natural products have been extracted, architecturally‐elucidated, synthesized, and chronicled by utilizing various synthetic methodologies in different fashions. Frequently, the synthesis of complex natural products proceed with inscrutable synthetic challenges, which can be circumvented either by modification of previously developed synthetic methods or by formulating a new one. In this way, a myriad of powerful synthetic reactions have been developed since the genesis of the logic of chemical synthesis. Amongst them, metathesis tactics discovered unexpectedly in the 1950s (Nobel Prize in 2005), have incredibly influenced and changed the landscape of the art of the total and formal synthesis in the last three A. H. Hoveyda, A. R. Zhugralin, me abruptly as compared to other developed transformations or their modified forms. In this particular review article, we envisioned to report a comprehensive detail of the metathetic tools involved in both total and fragments synthesis of natural products in the years 2018 and 2019 along with an overview of 2017.

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Hydrozirconation of Alkynes

Milligan,

Hammill,

Crocker

et al. 2023

Organic Reactions

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Since the first preparation of organozirconocenes from alkenes and alkynes in 1972, hydrozirconation has become one of the most commonly used stoichiometric methods to convert readily available starting materials into reactive but stable organometallic intermediates. A broad range of subsequent transformations may be employed to convert organozirconocenes in situ into high‐value functionalized products, often with the strategic formation of one (or several) new carbon–carbon bonds. This chapter focuses on the hydrozirconation of terminal and internal alkynes, and the subsequent synthetic transformations of the resulting alkenylzirconocenes. Zirconocene hydrochloride, Cp 2 Zr(H)Cl, is most frequently employed for the hydrozirconation step and can be used as a reagent or prepared in situ. Subsequent reactions of alkenylzirconocenes include additions to inorganic electrophiles such as halogens, as well as in situ ligand transfers to other metals, such as palladium and zinc, that further expand the range of accessible bond formations. The initial discussion focuses on the mechanism and stereochemical considerations, and on the steric and electronic factors that determine the regiochemistry of the either kinetically or thermodynamically controlled hydrozirconation. The “Scope and Limitations” section presents information on functional group compatibilities and is organized by the type of synthetic transformation of alkenylzirconocenes. Representative applications of the hydrozirconation of alkynes are showcased in syntheses of natural products, comparisons to alternative methods for the hydrometallation of alkynes. The goal of this chapter is to demonstrate the significance of hydrozirconation in organic synthesis, including the utility of the stoichiometric zirconium organometallics obtained from alkyne substrates, and to provide inspiration for the future development of new synthetic methods and strategies.

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Synthesis of the C1–C12 Fragment of Calyculin C

Cited by 6 publications

References 43 publications

Concise Total Synthesis of Dysoxylactam A and a Simplified Analog

Concise Total Synthesis of Dysoxylactam A and a Simplified Analog

Metathesis Reactions in Natural Product Fragments and Total Syntheses

Hydrozirconation of Alkynes

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