- First synthesis of (±)-pseudohygrophorone A12, an anti-fungal cyclohexenone derivative isolated from Hygrophorus abieticola
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Pseudohygrophorones A12 and B12 are cyclohexenone derivatives isolated from Hygrophorus abieticola (Basidiomycete) as anti-phytopathogenic compounds. In this study, the first synthesis of (±)-pseudohygrophorones A12 is rep
- Yamamoto, Yuzuki,Mori, Naoki,Watanabe, Hidenori,Takikawa, Hirosato
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- Studies on the diastereoselective allylation of aldehydes with enantiopure 2-sulfinylallyl building blocks
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A comparative study on the allylation of aldehydes with enantiopure (SS)-2-(p-tolylsulfonyl)-prop-2-en-1-ol (SS)-1a and the corresponding chloride (SS)-1b under two different reaction systems is reported. In general, better yields were obtained from chloride (SS)-1b, whereas higher diastereoinduction was observed from alcohol (SS)-1a. The sense of diastereoinduction is the same in both systems and the stereochemistry of the major diastereomer has been determined. Moreover, the configurational stability of the sulfoxide group on the resulting sulfinyl homoallylic alcohols 3 has been proven in each reaction system, which demonstrates the efficiency of the sulfoxide group as chiral auxiliary in these allylation processes. Finally, as an example of the synthetic potential of the resulting adducts, a total synthesis of natural enantioenriched (S)-nicotine from sulfinylalcohol 3h is reported.
- Marquez, Francesc,Llebaria, Amadeu,Delgado, Antonio
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p. 1625 - 1634
(2007/10/03)
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- Reagents for rapid peptide synthesis
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This invention relates to compounds of the formula: STR1 wherein R is an electron withdrawing group; R1 is H or COZ; X1 and X2 are independently H, lower alkyl, aryl, aryl lower-alkyl or polystyrene or R and X1 taken together with the carbon atoms to which they are attached form a ring containing from 4 to 15 ring carbon atoms and may contain up to 2 heteroatoms, wherein the heteroatoms are O, S, or N; and Z is an amino acid residue, a peptide residue or a leaving group. The compounds of the present invention are adaptable as blocking or protecting groups for an amine composition useful in peptide synthesis. The present invention is also directed to a method of protecting an amino group of an organic molecule during a reaction which modifies a portion of the molecule other than the protected amino group.
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- Synthesis of Alkenyl Sulphoxides by Intramolecular and Intermolecular Addition of Sulphenic Acids to Alkynes
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Alkyne-ω-sulphenic acids formed by thermolysis of ω-(t-butylsulphinyl)alkynes at 40 deg C cyclized regiospecifically to 2-methylenethiacycloalkane 1-oxides; 2-methylenethietan 1-oxide was not formed in this way. 2-Methylpropane-2-sulphenic acid, obtained by heating di-t-butyl sulphoxide, added regioselectively to oct-1-yne to give predominantly 2-t-butylsulphinyloct-1-ene, which itself decomposed thermally to a mixture of dioctenyl sulphoxides by way of alkenesulphenic acid-dialkyl sulphine interconversions.Benzenesulphenic acid, methanesulphenic acid, and ethoxycarbonylmethanesulphenic acid, conveniently generated by thermolysis of 1-cyano-2-alkyl(or aryl)sulphinylethanes, underwent intermolecular addition to unactivated and activated alkynes regioselectively to give alkenyl sulphoxides in good yields.
- Bell, Richard,Cottam, Peter D.,Davies, John,Jones, D. Neville
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p. 2106 - 2115
(2007/10/02)
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