Epoxidation of chiral camphor N-enoylpyrazolidinones with methyl(trifluoromethyl)dioxirane and urea hydrogen peroxide/acid anhydride: reversal of stereoselectivity.
نویسندگان
چکیده
Both diastereomeric isomers of epoxides with high optical purity are obtained when camphor N-methacryloylpyrazolidinone (1a) and N-tigloylpyrazolidinone (1b) are treated with a urea hydrogen peroxide/TFAA and methyl(trifluoromethyl)dioxirane, respectively.
منابع مشابه
A Highly Diastereoselective and Enantioselective Phase-Transfer Catalyzed Epoxidation of β-Trifluoromethyl-β,β-disubstituted Enones with H2O2
Trifluoromethylated organic compounds, especially chiral quaternary alcohols bearing trifluoromethyl group are of important intermediates in drugs, agrochemicals and etc.An efficient epoxidation of β-CF3-β,β-disubstituted unsaturated ketones (6) has been developed with environmental benign hydrogen peroxide as the oxidant and F5-substituted chiral qua...
متن کاملPreparation and Characterization of a Novel Biodegradable Epoxy Resin Modified with Epoxidized Oleic Acid
The goal of this research was to study the curing behavior and biodegradability DER 736 modified with epoxidized oleic acid. In this paper we demonstrate the efficient epoxidation of oleic acid with performic acid generated in situ from formic acid and hydrogen peroxide in the presence of H2SO4 as catalyst. The highest relative epoxy yield of 61% was achieved at 40 ͦC after 10 h. DER 736 modifie...
متن کاملUrea- hydrogen peroxide (UHP) oxidation of thiols to the corresponding disulfides promoted by maleic anhydride as mediator.
Urea-hydrogen peroxide (UHP) was used in the presence of maleic anhydride as mediator in a simple and convenient method for the oxidation in high yield of some thiols to the corresponding disulfides. Peroxymaleic acid formed in situ from the reaction of UHP with maleic anhydride has a key role in this oxidation. Performance of the reaction in various solvents showed that methanol was the solven...
متن کاملLipid Peroxide-Mediated Oxidative Rearrangement of the Pyrazinone Carboxamide Core of Neutrophil Elastase Inhibitor AZD9819 in Blood Plasma Samples.
This study focused on the mechanistic interpretation of ex vivo oxidation of a candidate drug in blood plasma samples. An unexpected lipid peroxide-mediated epoxidation followed by a dramatic rearrangement led to production of a five-membered oxazole derivative from the original six-membered pyrazinone-carboxamide core of a human neutrophil elastase inhibitor, 6-(1-(4-cyanophenyl)-1H-pyrazol-5-...
متن کاملA synthesis of γ-trifluoromethyl α,β-unsaturated γ-butyrolactones using CF(3)SiMe(3) as a trifluoromethylating agent.
A general synthesis of γ-trifluoromethyl α,β-unsaturated γ-butyrolactones is described. The fluoride-catalyzed nucleophilic addition of a trifluoromethyl (CF3) group generated from (trifluoromethyl)trimethylsilane (CF3SiMe3, Ruppert-Prakash reagent) to a masked maleic anhydride 1 (cyclopentadiene-maleic anhydride adduct) provides the corresponding adducts 2 with high stereoselectivity. The γ-tr...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of organic chemistry
دوره 68 25 شماره
صفحات -
تاریخ انتشار 2003