Propriétés de lissité de certaines normes

Sans résumé     

Total synthesis of the marine cytotoxic caulibugulones A-D

We report the first total synthesis of the cytotoxic marine alkaloids caulibugulone A-D. This synthesis confirmed the assigned structures and provided sufficient material for further biological testing.     

Biomimetic polyene cyclizations - asymmetric induction in the cyclization of a chiral dienic imine

The acid-catalyzed cyclization of the chiral aldimine prepared from trans-5,9 dimethyldeca-5,9-dienal and (?)S-α-phenyl-ethylamine affords diastereoisomeric amino-5 dimethyl-2,9 octalines, the asymmetric induction being 65% in the trans-trans series and 35% in the cis-trans series.     

Magnetic and magnetooptical properties of Au/Cu-wedge/15-Å-NiFe sandwiches

The results of an investigation of the magnetic and magnetooptical properties of Au/Cu-wedge/15-Å-NiFe sandwiches are reported. Oscillations of the equatorial Kerr effect as a function of the copper wedge thickness are observed. The period of these oscillations is found to be of the order of 5–6 Å. The experimentally observed oscillations of the equatorial Kerr effect are attributed to a quantum size effect. Pis’ma Zh. éksp. Teor. Fiz. 67, No. 1, 33–36 (10 January 1998)     

Polygermoxanes suitable for biochemical purposes. Part I. Digermoxanes (low-viscosity oils)

In order to replace silicones in some of their biomedical applications, e.g. syringe lubrication, implants ets., a series of digermoxanes (R¹R²R³Ge)₂O (R = n–alkyl, aryl) were synthesized. These compounds are thermally stable oils; their viscosities, depending on the nature of substituents, lie in the range 1–72 cPo (mPa s) at 20°C.     

Limites approximatives sur l'espace de Wiener

We use a stochastic integral which was first constructed by Nualart, Zakai and Ogawa, to show, for the variables of the second Wiener chaos, that the existence of this integral imply that these variables possess an approximate limit with respect to measurable norms defined by Gross. Moreover, this limit does not depend on the choice of the norm. Furthermore, we show that measurable norms possess an approximate limit with respect to quadratic norms. The main argument is a correlation inequality proved by Hargé.     

Reduction of β-ketosulfoxides : a highly efficient asymmetric synthesis of both enantiomers of methyl carbinols from the corresponding esters

It is shown that reductions of β-ketosulfoxides of identical chirality (R) at sulfur, lead to reduction products of opposite stereochemistry according to the reducing agent used. The high enantiomeric excesses obtained (80 to 100%) provide a general route to both enantiomers of methylcarbinols from the corresponding esters.