- A Very Efficient Alkene Epoxidation by Magnesium Monoperoxyphthalate Catalysed by Manganese Porphyrins
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Mn-porphyrins catalyse the epoxidation of various alkenes by magnesium monoperoxyphthalate: with 0.125-1 percent of tetra-2,6-dichlorophenylporphirinatomanganese(III) acetate as a catalyst, alkene conversion is nearly complete within 0.5-5 minutes at 0 de
- Querci, Cecilia,Ricci, Marco
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- Process for the production of 3,4-epoxybutyrate and intermediate therefor
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A 3,4-epoxybutyrate of the formula: STR1 wherein R1 is an alkyl or aralkyl group is efficiently prepared by a process comprising steps of: (a) reacting 3,4-dihydroxybutyronitrile of the formula: STR2 with a sulfonyl chloride of the formula: Rs
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- Process for the preparation of pyrrolidone derivatives
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Process for preparing pyrrolidinone derivatives of (1) STR1 in which R is hydrogen, alkyl or acyl characterized in that a compound of (2) STR2 wherein R1 is hydrogen and R2 is benzyl or substituted benzyl, or R1 and R2 can together form a group STR3 where R4 and R5 are independently hydrogen, alkyl, phenyl or optionally substituted aryl or together are 1,4-butylene or 1,5-pentylene; R3 is hydrogen or straight or branched alkyl of 1 to 4 carbon atoms; and X is alkyl subjected to N-deprotection and the deprotected intermediate is cyclized intramolecularly. The deprotected intermediates can be isolated as acid-addition salts.
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- Enzymatic Hydrolysis of Alkyl 3,4-Epoxybutyrates. A New Route to (R)-(-)-Carnitine Chloride
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The enzyme-catalyzed hydrolysis of alkyl 3,4-epoxybutyrates to the corresponding epoxy acids is reported.By using esterases the reaction occurred with good stereoselectivity leading to optically active unreacted esters of R configuration.With proteases the stereoselectivity was reversed, and the S enantiomer of the unreacted ester was recovered, albeit in lover enantiomeric excess.Finally, upon preliminary optimization of the reaction conditions, a new synthesis of (R)-(-)-carnitine chloride by the successive use of a stereoselective and of a nonstereoselective enzymatic hydrolysis is shown.
- Bianchi, Daniele,Cabri, Walter,Cesti, Pietro,Francalanci, Franco,Ricci, Marco
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p. 104 - 107
(2007/10/02)
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