One or More CC Bond(s) by Pericyclic Processes

Lebreton, Jacques; Guingant, André

doi:10.1016/b0-08-044655-8/00017-9

Cited by 3 publications

(1 citation statement)

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“…48 To perform this 1,2-dehydrogenation reaction, the lithium ketone enolate of 68 was treated with PhSeCl leading to an -phenylselenocarbonyl intermediate, which was transformed into the corresponding ,unsaturated compound [ 13 C 3 ]-56 in 68% overall yield (125 mg) using an oxidation-elimination sequence with NaIO 4 . 49 With the advanced intermediate [ 13 C 3 ]-56 in hand, application of a well-known sequence that includes hydrobromination with N-bromoacetamide, followed by epoxide formation from the resulting bromohydrin 69 and finally exposure to aqueous HF to promote solvolysis of the epoxide intermediate 70 and cleavage of the C17 bis(methylenedioxy) protecting group, gave the targeted [ 13 C 3 ]-dexamethasone 49 (14 mg) in 60% overall yield.…”

Section: Review Syn Thesismentioning

confidence: 99%

Synthesis of 13C-Labeled Steroids

Dénès

Farard²,

Lebreton

2019

Synthesis

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Due to the wide spectrum of biological activities of steroids, the detection and quantification of steroidal residues in various biological materials are crucial for drug development, doping prevention, and environmental protection. In addition, the analytical technique of stable isotopic dilution (SID) by Liquid Chromatography-Mass Spectrometry (LC-MS) requires 13C-labeled steroids as standards to provide accurate and reproducible steroid quantification. In this context, the synthesis of 13C-labeled steroids is reviewed. The approaches based on partial synthesis starting from commercially available steroids have been, by far, the most commonly employed strategy.1 Introduction2 Hemisynthesis of 13C3-Labeled Steroids via Partial Degradation of the A Ring2.1 Degradation of the A Ring to an Enol Lactone2.1.1 Introduction of 13C Atom(s) via Claisen Condensation: Turner’s Strategy2.1.2 Introduction of 13C Atom(s) with 13C-Labeled 5-(Diethylphosphono)pentan-2-one Ethylene Ketal Based on the Fujimoto–Belleau Reaction2.2 Degradation of the A Ring and Introduction of 13C Atom(s) with [13C3]-1-(Triphenylphosphoranylidene)propan-2-one3 Construction of the A Ring from an α,β-Unsaturated Ketone with 13C-Labeled 1-Iodo-3,3-(ethylenedioxy)butane as Electrophile4 Construction of the A and B rings: Stork’s Strategy5 Hemisynthesis with Introduction of 13C Atom(s) in the C17 Side Chain6 Conclusion

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Section: Review Syn Thesismentioning

confidence: 99%