Comportement hydromécanique d'un sol gonflant compacté sous très fortes succionsHydromechanical behaviour of a compacted swelling soil under very high suctions

This paper presents a study performed on a compacted swelling material in the range of suctions comprised between 8.5 and 287.9 MPa. Two series of tests were carried out with suction controlled oedometers. The aim of the first series was to study the compressibility as a function of suction. It showed that the apparent preconsolidation pressure and the plastic compression line are greatly affected by the applied suctions. The other series of tests highlighted the influence of complex hydromechanical paths on the compressibility of the studied material that appeared to be greatly influenced by the stress path followed. To cite this article: O. Cuisinier, F. Masrouri, C. R. Mecanique 331 (2003).     

New,Diastereoselective One‐Pot Synthesis of Tetrasubstituted Hydantoins

An effective route to hydantoins is described, based on the 2 : 1 : 1 addition of arylsulfonyl isocyanates, dialkyl acetylenedicarboxylates, and dialkyl trialkylsilyl phosphites. The resulting tetrasubstituted, stable hydantoins 4 / 4′ (Table) were obtained in excellent yields, and their structures were corroborated spectroscopically (IR, ¹H‐, ¹³C‐, ³¹P‐NMR, EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 2).     

One‐Step Synthesis of Dialkyl 2‐[(4‐Methylphenyl)sulfonyl]‐1H‐pyrrole‐3,4‐dicarboxylates by Reaction of Acetylenedicarboxylates with ‘Tosylmethyl Isocyanide’ (TsMIC) and Triphenylphosphine

The reactive 1 : 1 adducts in the reaction between Ph₃P and dialkyl acetylenedicarboxylates have been trapped with ‘tosylmethyl isocyanide’ (TsMIC ; 1 ) to yield dialkyl 2‐[(4‐methylphenyl)sulfonyl]‐1H‐pyrrole‐3,4‐dicarboxylates 3 (Scheme 1). The structures of the highly functionalized compounds 3 were corroborated spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 2).