Rafâa Besbes

(Z)-Dimethyl α-(bromomethyl)fumarate, an efficient intermediate for the selective synthesis of dimethyl 3-alkyl itaconates and 2-alkyl 3-carbomethoxy-γ-lactams

Abstract (Z)-Dimethyl α-(bromomethyl)fumarate 2 proved to be an efficient precursor of 3-substituted itaconic acid esters 3 via its reaction with magnesium dialkylcuprates. Some hindered esters 3 can be used for the diastereoselective synthesis of α-alkylated-β-methoxycarbonyl-γ-lactams 6 .

A One-Pot Synthesis of trans-N-Alkylaziridine-2-carboxylates from Amino Alcohol Esters

Abstract A series of new trans-N-alkylaziridine-2-carboxylates 3 was conveniently synthesized in a one-pot reaction by treatment of 1,2-amino alcohol mono and diesters 1 with methanesulfonyl chloride in the presence of (iPr)2NEt. The products were obtained in good to excellent yields with high trans-selectivity.

Practical Preparation of β‐Amino‐α‐Hydroxy Diesters: Key Intermediates for 1,4‐Oxazin‐2‐Ones

Abstract In the presence of a catalytic amount of amino acid hydrochloride, trans‐β‐phenylglycidic ester undergoes ring opening with high stereo‐ and regioselectivity when treated with glycine esters. Alkylation of the resulting β‐amino‐α‐hydroxy diesters with benzyl bromide, followed by cyclization to furnish the expected 1,4‐oxazin‐2‐ones, is also described.

A Simple and Direct Synthesis of Erythro‐β‐amino‐α‐hydroxy Esters from trans‐β‐Phenylglycidic Ester

Abstract trans‐β‐Phenylglycidic esters undergo ring opening when treated in tert‐butyl alcohol with primary amines (R–NH2, with R = secondary group or tertiary group), which attacks epoxide exclusively at C‐3 and avoids aminolysis of the ester group affording the erythro‐β‐amino‐α‐hydroxy esters as the sole product.

Stereoselective Synthesis of cis- and trans-3,4,5-Trisubstituted-1,3-oxazolidin-2-one Derivatives from 1,2-Amino Alcohol Monoesters and Aziridine-2-carboxylates

Abstract New cis-N-alkyl-1,3-oxazolidin-2-ones were prepared in moderate to good yields via phosgenation of erythro-1,2-aminoalcohol monoesters, accompanied by formation of aziridine by-products. On the other hand, their regioisomers trans-N-alkyl-1,3-oxazolidin-2-ones were prepared regio- and stereoselectively in good yields by ring expansion of trans-N-alkyl aziridine-2-carboxylates. GRAPHICAL ABSTRACT

Convenient Synthesis of 1,2-Diamines from β-Chloro Amines: Precursors of New Substituted Piperazin-2-ones

Abstract A practical synthesis of 1,2-diamines from β-chloro amines is reported. The reaction proceeds through the intermediacy of an aziridinium ion opening by amines. The conversion of these diamines into polysubstituted piperazinones is also investigated. Supplemental materials are available for this article. Go to the publishers online edition of Synthetic Communications® to view the free supplemental file. GRAPHICAL ABSTRACT

Straightforward Synthesis of 1,2-Amino Phosphate Diesters and Application to the Synthesis of Novel 1,2-Amino Ether Diesters

A variety of 1,2-amino alcohol diesters 1 reacted smoothly with diethyl chlorophosphate under basic conditions to afford the corresponding 1,2-amino phosphate diesters 2 in excellent yields. These compounds served as useful precursors for subsequent nucleophilic attack by alcohols in an SN2 fashion to provide 1,2-amino ether diesters 3.

Stereoselective synthesis of 4-hydroxymethyl-1,3-oxazolidin-2-one derivatives from novel 2-hydroxymethylaziridines

Abstract A stereoselective and simple method for the synthesis of trans-2-hydroxymethyl-N-alkyl-1,3-oxazolidin-2-ones is described. The synthesis involved the reduction of trans-aziridine-2-carboxylates with LiAlH4, followed by a ring opening and a cyclization reaction in the presence of methyl chloroformate to afford the target trans-oxazolidinones in completely regio- and stereoselective process. A plausible reaction mechanism has been proposed involving an SN1 pathway and a detailed computational study of this mechanistic process has been carried out using theoretical calculations. Graphical Abstract

Crystal structure of ethyl 2-(4-chlorophenyl)-3-cyclopentyl-4-oxo-1-propyl-imidazolidine-5-carboxylate.

The title compound, C20H27ClN2O3, was obtained via an original synthesis method. The central heterocyclic ring adopts a shallow envelope conformation, with the N atom bearing the cyclopentane ring as the flap [deviation from the other atoms = 0.442 (2) Å]. The cyclopentane ring adopts a twisted conformation about one of the CN—C bonds: the exocyclic C—N bond adopts an equatorial orientation. The dihedral angles between the central ring (all atoms) and the pendant five- and six-membered rings are 10.3 (2) and 87.76 (14)°, respectively. In the crystal, C—H⋯O interactions link the molecules into [011] chains. A weak C—H⋯Cl interaction links the chains into (100) sheets. A mechanism for the cyclization reaction is proposed.

Amino Phosphate Monoesters: A Convenient Source of 2-Alkylamino-3-methoxy-3-phenylpropionates via Aziridinium Ions

Abstract The synthesis of a series of amino ethers was carried out in a two-step method involving phosphorylation of the corresponding amino alcohols and subsequent double displacement via an aziridinium intermediate. The new products were obtained in good yields with excellent regioselectivity. GRAPHICAL ABSTRACT