Giuliana Righi

Highly regioselective opening of optically active N-Boc-2,3-aziridino alcohol derivatives with metal halides

Abstract Chiral 3-substituted N-Boc-2,3-aziridino alcohols are opened in a regio and stereoselective fashion by MgBr 2 ; the obtained 3-bromo derivatives can be reduced and deprotected under mild conditions to the corresponding 1,2-amino alcohols.

Regioselective opening of 3-Substituted N-Ethoxycarbonyl aziridine-2-carboxylates with metal halides toward the preparation of α and β-amino acids

Abstract 3-Substituted N-Ethoxycarbonyl aziridine-2-carboxylates are opened in a regio and stereoselective fashion whether in C-2 position by NaX (X = 1, Br) or in C-3 by MgBr 2

Improved Procedure for the Reduction of Esters to Alcohols by Sodium Borohydride

Abstract An improved procedure for the employment of NaBH4 in the reduction of ester function is described.

Metal halide-mediated opening of three membered rings: enantioselective synthesis of (2S,3R)-3-amino-2-hydroxydecanoic acid and (3R)-3-aminodecanoic acid

Abstract Regio and stereoselective opening of three membered rings by metal halides was utilized for the enantioselective synthesis of (2 S ,3 R )-3-amino-2-hydroxydecanoic acid and (3 R )-3-aminodecanoic acid.

An easy approach to dihydrofurans by one-step cyclisation of 2-alkenyl substituted 1,3-dicarbonyl compounds

Abstract Dihydrofuran derivatives were obtained by a simple one-step procedure involving an easy epoxidation of 2-alkenyl-1,3-dicarbonyl compounds by dimethyldioxirane prepared in situ and a subsequent cyclisation under the same basic reaction conditions.

A study on the chelation control in the regioselective opening of 2,3-bifunctionalized epoxides

Abstract The results obtained in the MgBr 2 -mediated opening of 2,3-bifunctionalized epoxides are reported. The studies showed that the chelation control of MgBr 2 between different functionalities can in some cases be selective.

A mild preparation of α-halo-α,β-enones from cyclic enones

Abstract A simple one pot procedure for the selective transformation of cyclic enones into α-halo-α,β-enones is reported using dimethyldioxirane and metal halides/Amberlyst 15. The method appears particulary appealing for the preparation of labelled molecules for use with the CMIA techinique.

A simple route to syn α-Amino-β-Hydroxy esters by C-2 regioselective opening of a, β-Epoxy esters with metal halides

Abstract α,β-Epoxy esters are opened by NaX (X = I, Br) in a regio and stereoselective fashion to β-hydroxy-α-halo esters, which represent suitable precursors of syn α-amino-β-hydroxy esters and β-hydroxy esters.

Stereo- and regioselective ring opening of alkenyl aziridines with metal halides

The reaction of N-Boc-alkenyl aziridines with lithium halides in presence of Amberlyst 15 afforded the stereo- and regioselective ring-opened products in high yields. The following treatment of the bromo- and iododerivatives with silica gel produced the corresponding oxazolidin-2-ones.

Enzyme-catalyzed desymmetrization of meso-skipped polyols to useful chiral building blocks

Abstract the biocatalytic desymmetrization, in presence of different enzymes, of two models of polyfunctionalized diols in a meso form was studied PFL was found to be the most selective enzyme with excellent results in chemical and optical yield with some of the tested substrates. The obtained chiral building block was utilized for some useful synthetic transformations toward the synthesis of natural products