Phenylselenoetherification. A highly efficient cyclization process for the synthesis of oxygen- and sulfur-heterocycles

Nicolaou, K. C.; Magolda, R. L.; Sipio, W. J.; Barnette, W. E.; Lysenko, Zenon; Joullié, Madeleine M.

doi:10.1021/ja00531a020

Cited by 129 publications

(67 citation statements)

References 17 publications

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“…After drying over Na 2 SO 4 and concentration, the residue was purified by chromatography over silica with dichloromethane to give H 3 ]-2-phenylselenyl-1,8-cineole (3) as a yellow residue. Reduction of the latter to remove the phenylselenyl group was performed as described by Nicolaou et al [14] using tri-n-butyltin hydride (150 mL, 0.5 mmol) and azobisisobutyronitrile (0.02 mol/L in toluene, 300 mL, 6 mmol) in toluene at 1101C for 1 h.…”

Section: Synthesis Of [9-2 H 3 ]-18-cineole (4)mentioning

confidence: 99%

Quantification of 1,8‐cineole and of its metabolites in humans using stable isotope dilution assays

Horst

Rychlik

2010

Molecular Nutrition Food Res

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The metabolism of 1,8-cineole after ingestion of sage tea was studied. After application of the tea, the metabolites 2-hydroxy-1,8-cineole, 3-hydroxy-1,8-cineole, 9-hydroxy-1,8-cineole and, for the first time in humans, 7-hydroxy-1,8-cineole were identified in plasma and urine of one volunteer. For quantitation of these metabolites and the parent compound, stable isotope dilution assays were developed after synthesis of [(2)H(3)]-1,8-cineole, [9/10-(2)H(3)]-2-hydroxy-1,8-cineole and [(13)C,(2)H(2)]-9-hydroxy-1,8-cineole as internal standards. Using these standards, we quantified 1,8-cineole by solid phase microextraction GC-MS and the hydroxyl-1,8-cineoles by LC-MS/MS after deconjugation in blood and urine of the volunteer. After consumption of 1.02 mg 1,8-cineole (19 μg/kg bw), the hydroxycineoles along with their parent compound were detectable in the blood plasma of the volunteer under study after liberation from their glucuronides with 2-hydroxycineole being the predominant metabolite at a maximum plasma concentration of 86 nmol/L followed by the 9-hydroxy isomer at a maximum plasma concentration of 33 nmol/L. The parent compound 1,8-cineole showed a low maximum plasma concentration of 19 nmol/L. In urine, 2-hydroxycineole also showed highest contents followed by its 9-isomer. Summing up the urinary excretion over 10 h, 2-hydroxycineole, the 9-isomer, the 3-isomer and the 7-isomer accounted for 20.9, 17.2, 10.6 and 3.8% of the cineole dose, respectively.

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Section: Synthesis Of [9-2 H 3 ]-18-cineole (4)mentioning

confidence: 99%

Quantification of 1,8‐cineole and of its metabolites in humans using stable isotope dilution assays

Horst

Rychlik

2010

Molecular Nutrition Food Res

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“…Depending on the reaction conditions, the formation of seleniranium ion can be reversible process and at low temperatures usually under kinetic control [10,22]. While the selenocyclofunctionalization of primary and secondary alkenols is usually driven by electronic factors, and formation of corresponding fiveor six-membered rings occurs in Markovnikov fashion (regioselectivity), the effect of steric hindrances is decisive in the course of tertiary alkenol transformation, where the product of anti-Markovnikov's rule can be expected.…”

Section: Resultsmentioning

confidence: 99%

“…Thus, the development of methods that enable access to their effective construction is of significant importance, and many strategies have been explored for this purpose [5][6][7][8][9]. It is now well established that selenium-induced cyclofunctionalization of unsaturated alcohols represents an easy access to a wide variety of heterocyclic compounds containing oxygen atom [10,11]. This synthetic method has the advantage that the introduction of the heteroatom, the manipulation of the obtained product and the removal of the function from the side chain is facilitated by simple and mild experimental conditions.…”

Section: Introductionmentioning

confidence: 99%

Kinetic and mechanistic insight into Lewis base and acid-mediated phenylselenoetherification of 2,6-dimethyl-hept-5-en-2-ol

et al. 2015

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Mechanistic and kinetic aspects, as well as quantum chemical calculations, for the formation of a tetrahydrofurane ring by cyclization of the highly substituted alcohol-2,6-dimethyl-hept-5-en-2-ol with phenylselenohalides (PhSeCl and PhSeBr), in the presence of various Lewis bases (piperidine, triethylamine, pyridine and quinoline) and Lewis acids (CoCl 2 , SnCl 2 ) as additives were studied. The substituted tetrahydrofuran ring is common motif in many natural products, especially in bioactive marine macrolides. Due to the presence of additives in reactions, the high regioselectivity was achieved, and the tetrahydrofuran type of ether in all studied reactions was obtained in excess in regard to the six-membered cyclic ether. In addition, kinetic aspects of reactions mediated by Lewis bases were studied by UV-Vis spectroscopy (in THF, at 288 K), as reactions of pseudo-first-order. Obtained values for rate constants proved catalytic role of additives and indicated that the reaction rate depends on pKa values of used base as well as on their ability for formation of hydrogen bond with OH-alcohols group.

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“…The cyclic ether products were known compounds, and their spectral data had been given previously in the literature [30]. Reduction was performed according to the procedure described earlier [31].…”

Section: Methodsmentioning

confidence: 99%

A simple, convenient and expeditious approach to cineol

Bugarčić

Dunkić

Mojsilović

2004

Heteroatom Chemistry

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Phenylselenoetherification. A highly efficient cyclization process for the synthesis of oxygen- and sulfur-heterocycles

Cited by 129 publications

References 17 publications

Quantification of 1,8‐cineole and of its metabolites in humans using stable isotope dilution assays

Quantification of 1,8‐cineole and of its metabolites in humans using stable isotope dilution assays

Kinetic and mechanistic insight into Lewis base and acid-mediated phenylselenoetherification of 2,6-dimethyl-hept-5-en-2-ol

A simple, convenient and expeditious approach to cineol

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