• Citations Per Year
Learn More
The molecular mechanism for the intramolecular [5 + 2] cycloaddition reaction of beta-silyloxy-gamma-pyrones bearing tethered alkenes has been characterized using ab initio methods. A comparative study for this sort of cycloaddition carried out at different computational levels points out that the B3LYP/6-31G calculations give similar barriers to those(More)
Background: Colorectal cancer is the second most frequent tumour in developed countries. Survival in colorectal cancer depends mostly of disease stage at the time of diagnosis; it seem reasonable therefore, that those individuals with symptoms or signs suspicious of colorectal cancer should be investigated without delay in order to have an early diagnosis.(More)
We have investigated several 1,3-dipolar cycloadditions of a chiral nitrone prepared from L-erythrulose. While cycloadditions to carbon-carbon multiple bonds of dipolarophiles such as ethyl acrylate, ethyl propiolate, or dimethyl acetylenedicarboxylate were poorly stereoselective, reaction with acrylonitrile provided predominantly one diastereomeric adduct.(More)
Polyfunctionalized, unprotected reagents (e.g. amines and thiols) can be used in the production of highly diverse compound libraries by performing sequential nucleophilic substitutions on support-bound polyelectrophiles (see scheme). The procedure reported here enables the efficient preparation of new beta-alanine derivatives which are suitable for lead(More)
  • 1