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Propargyl alcohol sulfur

The procedure described is that of Wille and Saffer. Propiolaldehyde has also been prepared by the oxidation of propargyl alcohol using ammonium dichromate or manganese dioxide in 10% sulfuric acid. Propiolaldehyde has also been prepared by warming the dimethyl or diethyl acetal with dilute sulfuric acid. ... [Pg.68]

The reaction of the propargyl alcohols 53 with the reagent 54 furnished the S-alle-nylsulfinylamines 55 in good to excellent yields [108, 109]. Furthermore, the propargyl alcohols can be transformed with sulfur dichloride to the S-allenylsulfmates 56, which isomerize on heating in solution to the diallenyl sulfones 57 [79, 110, 111]. [Pg.366]

In addition to the sulfur-substituted enyne-allenes depicted in Schemes 20.18-20.20, the sulfoxide 141 was prepared by treatment of the enediynyl propargylic alcohol 108 with benzenesulfenyl chloride to induce a [2,3]-sigmatropic rearrangement (Scheme 20.29) [10]. The Myers-Saito cyclization of 141 occurs at 37 °C with a half-life of only 16 min. [Pg.1109]

The impressive activity achieved by Teles catalyst was improved some years later by the use of CO as an additive [92]. In this study, Hayashi and Tanaka reported a TOF of 15600h 1, at least two orders of magnitude higher than [as-PtCl2(tppts)2], for the hydration of alkynes, providing an alternative synthetic route to the Wacker oxidation. Although several solvents were tested, the best results were obtained with aqueous methanol, and sulfuric acid or HTfO as acidic promoters. Unlike Utimoto s observation, in this case terminal propargylic alcohols partially (17-20%) delivered anti-Markovnikov product, in addition to the Markovnikov species. Some years before, Wakatsuki et al. had already reported the anti-Markovnikov hydration of terminal alkynes catalyzed by ruthenium(II) [93]. [Pg.450]

In 1988 Gibbs and Okamura [128] described the intramolecular Diels-Alder reaction of the non-racemic vinylallene 150 to afford the adduct 151 (as a mixture of epimers at sulfur) in a completely exo-selective manner, due to the topographical and steric arrangement of the starting vinylallene (Scheme 74). Compound 150 was obtained as a mixture of epimers at sulfur from the optically pure propargylic alcohol 149 (this transformation involved a sulfoxide-sulfenate rearrangement). Compound 151 was used to synthesize (-l-)-sterpurene. [Pg.78]

In the case of steroidal propargylic alcohols the first rearrangement produced a mixture of allenyl sulfoxides, epimeric at the sulfur atom, which reacted with an added nucleophile to produce substituted allylic sulfoxides. Rearrangement of the sulfoxide resulted in the exclusive formation of a-hydroxy derivatives. This reaction sequence has been applied in a synthesis of hydrocortisone acetate74 (Nu = OCH3) from androstene-3,17-dione and in a transformation of mesantrol75 (Nu = malonate) to a spirolactone. [Pg.498]

Yoshimatsu, M., Naito, M., Kawahigashi, M., Shimizu, H., Kataoka, T. Meyer-Schuster Rearrangement of y-Sulfur-Substituted Propargyl Alcohols A Convenient Synthesis of a,P-Unsaturated Thioesters. J. Org. Chem. 1995, 60,4798-4802. [Pg.628]

Dowex 50 ion-exchange resin is treated with a solution of mercury sulfate in dilute sulfuric acid, then carefully washed and dried. This resin (2 g) is added, with stirring, to a solution of propargyl alcohol (10.4 g, 0.2 mole) in water (100 ml) the temperature rises to 55° within 13 min, The mixture is stirred for 25 min at 50° and subsequently at 40°. After 100 min the resin is filtered off and washed with water (20 ml). An aliquot part (12 ml) of the solution is treated with phenylhydrazine, giving hydroxyacetone phenylhydrazone (2.85 g, 87%), m.p. 99-101DC. [Pg.286]

Propargyl alcohol (15.1 mol, 848 g, freshly distilled), methanol (59.6 mol, 1908 g), and concentrated sulfuric acid (15 mmol, 1.47 g) were mixed and heated to 55 °C. A solution of Ph3PAuMe (148 pmol, 70.4 mg) in 125 mL of dioxane was then added within 10 h. The mixture was stirred for an additional 10 h, and then most of the remaining methanol was removed by distillation at reduced pressure. The residual solution was neutralized with 30% sodium methanolate in methanol and cooled in an ice bath. Precipitated product was collected by filtration and dried. A second batch of product can be obtained by further concentration of the mother liquor. Total yield of isolated product 1238 g (93%). [Pg.486]

A Pd-catalyzed carbonylative coupling reaction of propargyl alcohols and thiols has been developed by using different reaction conditions. Monothioesters, dithioesters, or sulfur-containing furanones can be produced in good to excellent yield and selectivity. This methodology is attractive for the preparation of thioesters and sulfur-substituted... [Pg.697]

An innovative procedure for the synthesis of sulfur- or selenium-containing lactones from propargyl or homopropargyl alcohols involves the formal addition of ArS-Pd-X or ArSe-Pd-X to a multiple bond as the key stepJ" When a propargyl alcohol is treated with CO under Pd(0) catalysis in the presence of diarylsulfldes or diarylselenides, buteno-lides substituted in the /S-position with S- or Se-based residue are formed (Scheme 30). [Pg.712]


See other pages where Propargyl alcohol sulfur is mentioned: [Pg.83]    [Pg.67]    [Pg.878]    [Pg.742]    [Pg.742]    [Pg.96]    [Pg.415]    [Pg.797]    [Pg.266]    [Pg.465]    [Pg.408]    [Pg.139]    [Pg.83]    [Pg.44]    [Pg.97]    [Pg.86]    [Pg.768]    [Pg.879]    [Pg.550]    [Pg.196]    [Pg.284]    [Pg.285]    [Pg.768]    [Pg.89]    [Pg.285]    [Pg.83]    [Pg.539]    [Pg.869]    [Pg.905]    [Pg.99]    [Pg.178]    [Pg.2506]    [Pg.20]    [Pg.173]    [Pg.4923]    [Pg.5018]    [Pg.5524]    [Pg.486]   
See also in sourсe #XX -- [ Pg.161 , Pg.235 ]




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Propargyl alcohol

Propargylic alcohols

Sulfur alcohols

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