302. The epoxide–episulphide transformation

Hall, Laurance D.; Hough, L.; Pritchard, R. A.

doi:10.1039/jr9610001537

Cited by 52 publications

(10 citation statements)

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“…In our first approach (Scheme 3), the commercially available D-glucurono-6,3-lactone ( 5) was converted to 21 by treatment with a catalytic amount of toluenesulfonic acid in acetone in the presence of the hydroxyl group in the R position. Following a literature procedure, 23 the adduct 21 was then reacted with toluenesulfonic chloride in the presence of pyridine, yielding the corresponding tosylate 22. The tosylate 22 was transformed to the bromide 23 (as a diastereomeric mixture) with lithium bromide in DMF solvent based on a literature procedure.…”

Section: Resultsmentioning

confidence: 99%

“…A solution of 31 (4.38 g, 12.6 mmol) and lithium bromide (4.96 g, 57 mmol) in acetone (110 mL) was stoppered and stirred at room temperature for 1 h. After the solvent was removed, the residue was suspended in ether (100 mL) and washed with water (3 × 100 mL) and brine. After being dried over magnesium sulfate and filtered, the solution was concentrated to produce 23a 23 (3.40 g, 97% yield) as a white solid. IR (film): 1792, 1377, 1169, 1061, 1018 cm -1 .…”

Section: -Deoxy-12-o-isopropylidene-r-d-glucofuranurono-63-lactone (25)mentioning

confidence: 99%

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Regio- and Diastereoselective Allenylation of Aldehydes in Aqueous Media: Total Synthesis of (+)-Goniofufurone¹

Meng

Hua

et al. 1998

J. Org. Chem.

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The regio- and diastereoselectivities of metal-mediated allenylation of carbonyl compounds were investigated in aqueous media. Different metal mediators showed varied regioselectivities on product formation during propargylation-allenylation reactions of carbonyl compounds with simple propargyl bromide. Under the standard reaction conditions, the use of indium provided the highest regioselectivity, with a preference of formation of the homopropargyl alcohol. The use of tin and bismuth as the metal mediator provided slightly lower selectivities with the same preference. The use of zinc and cadmium as the mediators further lowered the product selectivity. The reactions of an aliphatic aldehyde with simple propargyl bromide showed a lower selectivity than the reaction of an aromatic aldehyde in most cases, except for the use of tin or zinc (where comparable selectivities were observed). On the other hand, the reaction of terminal-substituted propargyl bromides with aldehydes mediated by indium showed a high regioselectivity in forming allenylation products. The indium-mediated allenylation of carbonyl compounds bearing an alpha-hydroxyl group also proceeded with a high diastereoselectivity, forming syn-diols predominantly in aqueous ethanol. The high diastereoselectivity in allenylation of alpha-hydroxyl-substituted aldehydes was attributed to the chelation effect exhibited by the alpha-hydroxyl substitutent. Through the use of this highly diastereoselective allenylation, (+)-goniofufurone was synthesized from D-glucurono-6,3-lactone.

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Section: Resultsmentioning

confidence: 99%

Section: -Deoxy-12-o-isopropylidene-r-d-glucofuranurono-63-lactone (25)mentioning

confidence: 99%

Regio- and Diastereoselective Allenylation of Aldehydes in Aqueous Media: Total Synthesis of (+)-Goniofufurone¹

Meng

Hua

et al. 1998

J. Org. Chem.

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“…vic -Diols have been widely used as precursors for the synthesis of episulfides and olefins, which are very versatile functions in organic synthesis. The synthesis of episulfides generally involves the previous transformation of the diol into the corresponding epoxide and opening with thiocyanate ions or with thiourea, − which are the most common reagents used for this transformation. A recently described method for the synthesis of thiiranes involves a previous transformation of allylic alcohols into cyclic xanthates. − Olefins can be obtained from vic -diols by a variety of different methods. , For example, direct conversion of vic -diols into alkenes is possible by treatment with tungsten reagents, titanium metals, , Me 3 SiCl−NaI, Ph 3 P−imidazole−I 2 , and PBr 3 −CuBr−ether followed by zinc powder …”

Section: Introductionmentioning

confidence: 99%

Applications of Cyclic Sulfates ofvic-Diols: Synthesis of Episulfides, Olefins, and Thio Sugars

et al. 1997

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A new efficient and expeditious one-pot synthesis of thiiranes and olefins from cyclic sulfates of vic-diols is described. Opening of cyclic sulfates with potassium thioacetate or potassium thiocyanate followed by treatment with sodium methoxide led to episulfides. Olefins were obtained when potassium selenocyanate was used as nucleophile, and the obtained monoesters were treated with sodium borohydride. This method was applied to acyclic polyols derived from chiral glycerine, 1,2-isopropylidenehexofuranoses with different subtituents at C-3, and dimethyl acetals derived from pentoses and hexoses. The methodology is highly versatile, and its applicability has been demonstrated by the synthesis of different 4- and 5-thiosugars by opening of the thiirane ring with sodium acetate or lithium aluminum hydride. Reduction with lithium aluminum hydride of the thiocyanate sulfate potassium salt obtained by the opening of cyclic sulfate with KSCN allowed the direct synthesis of 5-deoxy-4-thio- and 6-deoxy-5-thiosugars. Cyclic thiosugars with the sulfur atom in the ring are obtained by acidic hydrolysis of the 5-thiol derivatives of 1,2-O-isopropylidenehexofuranoses and 4-thiopentose dimethyl acetals. Using this method, an efficient synthesis of 5-thio-l-fucose as well as the synthesis of 2,5-dideoxy-4-thiofuranose is described.

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“…SYNTHESIS AND CHEMICAL BEHAVIOUR 221 Compound £: l K NMR 6 1.05 (t, 3H, J^ 5 =6.5 Hz, 1.887 (qd, 2H, C ( 4 ) H 2 ) , 3.1 and 3.15 (2s,'6H, 2CH 3 S0 2 >, 3.48 and 3.51 (2s, 6H, 2OCH 3 HydroRenation of Olefin 1_. A mixture of 1_ (0.152 g, 0.48 mmol) in acetic acid (1.5 mL) was hydrogenated in the presence of PtO 2 (0.017 g) at atmospheric pressure for 4 h. The catalyst was filtered off and washed with 1:1 chloroform-toluene.…”

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confidence: 99%

Synthesis and Chemical Behaviour of 4, 5-Dideoxy-4, 5-Epithio-2, 3-DI-0-Methanesulfonyl-L-Xylose Dimethyl Acetal

Miljković¹,

Popsavin²,

Vukojević³

et al. 1990

Journal of Carbohydrate Chemistry

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302. The epoxide–episulphide transformation

Cited by 52 publications

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Regio- and Diastereoselective Allenylation of Aldehydes in Aqueous Media: Total Synthesis of (+)-Goniofufurone¹

Regio- and Diastereoselective Allenylation of Aldehydes in Aqueous Media: Total Synthesis of (+)-Goniofufurone¹

Applications of Cyclic Sulfates ofvic-Diols: Synthesis of Episulfides, Olefins, and Thio Sugars

Synthesis and Chemical Behaviour of 4, 5-Dideoxy-4, 5-Epithio-2, 3-DI-0-Methanesulfonyl-L-Xylose Dimethyl Acetal

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302. The epoxide–episulphide transformation

Cited by 52 publications

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Regio- and Diastereoselective Allenylation of Aldehydes in Aqueous Media: Total Synthesis of (+)-Goniofufurone1

Regio- and Diastereoselective Allenylation of Aldehydes in Aqueous Media: Total Synthesis of (+)-Goniofufurone1

Applications of Cyclic Sulfates ofvic-Diols: Synthesis of Episulfides, Olefins, and Thio Sugars

Synthesis and Chemical Behaviour of 4, 5-Dideoxy-4, 5-Epithio-2, 3-DI-0-Methanesulfonyl-L-Xylose Dimethyl Acetal

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Regio- and Diastereoselective Allenylation of Aldehydes in Aqueous Media: Total Synthesis of (+)-Goniofufurone¹

Regio- and Diastereoselective Allenylation of Aldehydes in Aqueous Media: Total Synthesis of (+)-Goniofufurone¹