Androstanes with Modified Carbon Skeletons

Norden, Sascha; Bender, Matthias; Rullkötter, Jürgen; Christoffers, Jens

doi:10.1002/ejoc.201100390

Cited by 14 publications

(5 citation statements)

References 29 publications

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“…Materials : The compounds DMFLTPD, DMFLTPD‐ d 36 and 1 were prepared as described in the literature, while α‐NPD, mCP, TPBi and coronene‐ d 12 were obtained commercially and purified by train sublimation before use.…”

Section: Methodsmentioning

confidence: 99%

“…In these systems, the nonradiative decay processes of the guest emitters are effectively suppressed by the rigid host matrices . Based on this idea, we obtained LLP of over 1 s from a mixture of a hydroxyl steroid and aromatic emitters . The hydroxyl steroid host provides a rigid amorphous environment for guest emitters, which minimizes the nonradiative decay of the long‐lived triplet excitons.…”

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confidence: 99%

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Afterglow Organic Light‐Emitting Diode

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Section: Methodsmentioning

confidence: 99%

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confidence: 99%

Afterglow Organic Light‐Emitting Diode

et al. 2015

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“…In our previous synthetic studies, we prepared steranes 1 – 3 (Figure 1), all of which have m / z = 260 [M] + 2. Their mass spectra and gas chromatographic retention times were compared with those of the putative unknown C 19 steranes.…”

Section: Introductionmentioning

confidence: 99%

Identification of a Fossil Sterane Biomarker in Crude Oil – an Androstane with a Modified Carbon Skeleton

et al. 2013

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Three constitutional isomers of androstane were prepared for comparison with three unknown fossil C19H32 organic biomarkers (“19A”, “19B”, and “19C” in elution order) in geological samples from Oman. 3β‐Methyl‐A‐nor‐androstane was prepared in six steps (8 % overall yield) from testosterone. The key steps of this sequence were an Eschenmoser fragmentation and recyclization of the A ring. A mixture of four stereoisomers of 3‐methyl‐A‐nor‐androstane (4 % overall yield) was prepared by ionic hydrogenation of the olefin after A‐ring recyclization in three steps. 17‐Methyl‐18‐nor‐androstane was synthesized in four steps as a mixture of isomers (58 % overall yield) from dihydrotestosterone with a Wagner–Meerwein shift of the 13β‐methyl group to C‐17 as the key step. Pure 17β‐ and 17α‐methyl‐18‐nor‐13α‐androstane (4 and 2 % overall yield, respectively) were obtained in three additional steps after α‐oxidation of the Wagner–Meerwein rearrangement product and subsequent reduction. The synthesis of 18‐nor‐D‐homo‐13β‐androstane (12 % yield over seven steps from dihydrotestosterone) involved oxidative cleavage of the C–C double bond in the Wagner–Meerwein rearrangement product from the previous synthesis and subsequent recyclization of the D ring followed by reduction. The relative configurations of all final products were confirmed by X‐ray crystallography. A comparison of the synthetic standards with the saturated hydrocarbon fraction of an Oman crude oil by gas chromatography (GC–MS) coinjection on three different GC columns and comparison of mass spectra revealed that unknown compound 19C is 18‐nor‐D‐homo‐13β,14α‐androstane, whereas the isomeric 3‐methyl‐A‐nor‐androstanes and 17‐methyl‐18‐nor‐androstanes elute close to 19A and 19B, respectively, but do not match the unknowns.

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“…[9][10][11][12] Among the main organic reactions, initial free radical two-step Barton decarboxylation and recent advances offer the possibility to create various structures. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] It is noteworthy that solvent and especially water plays an important role in free radical chemistry. 33,34 Maleimide derivatives can be considered as either interesting target compounds [35][36][37][38][39][40] or organic synthons/monomers.…”

Section: Introductionmentioning

confidence: 99%

One-step Barton decarboxylation by micellar catalysis – application to the synthesis of maleimide derivatives

2015

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Maleimides being studied or used in various applications, for the first time, a facile entry to Barton decarboxylation in aqueous media is described to obtain in one step substituted N-phenylmaleimide synthons. The radicals, generated by the ultrasonic lysis of N-hydroxy-2-thiopyridone esters, reacted respectively with electron deficient olefin phenylmaleimide in a one-step radical addition. These esters were obtained from natural fatty acid derivatives including unsaturated ones. Various activating conditions (UV, sonication, heating, microwaves), reactants and solvent adjustment, as well as surfactants were tested to improve the yield of the reaction. One of the products obtained was then transformed into a new electron-trap monosubstituted maleimide and was able to react again to obtain a disubstituted N-phenylmaleimide derived from biomass.

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Androstanes with Modified Carbon Skeletons

Cited by 14 publications

References 29 publications

Afterglow Organic Light‐Emitting Diode

Afterglow Organic Light‐Emitting Diode

Identification of a Fossil Sterane Biomarker in Crude Oil – an Androstane with a Modified Carbon Skeleton

One-step Barton decarboxylation by micellar catalysis – application to the synthesis of maleimide derivatives

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