First general approach to cyclohex-3-ene-1,1-bis(phosphonates) by Diels-Alder cycloaddition of tetraethyl vinylidenebis(phosphonate) to 1,3-dienes.

Tetraethyl vinylidenebis(phosphonate) (VBP) reacts smoothly with substituted 1,3-dienes at 90-110 degrees C without solvent to give the corresponding cyclohex-3-ene-1,1-bis(phosphonates) in good yields (60-85%). With nonsymmetrically substituted dienes, mixtures of regioisomers are obtained, the regioisomeric ratio being exclusively controlled by electronic effects. Danishefsky's diene allows tetraethyl 4-oxocyclohex-2-ene-1,1-bis(phosphonate) to be obtained in an 81% overall yield after the acid-catalyzed hydrolysis of the Diels-Alder cycloadduct.

[Use of the Cerebral Function Monitor in general anesthesia].

The Monitor of Cerebral Function was used in clinical anaesthesia for a wide range of procedures: both with and without inhalation anaesthesia, (halothane and enflurane); -intravenous anaesthesia, barbiturate or neuroleptanalgesia; -regional intravenous anaesthesia. The examination of the traces shows the importance of this type of monitoring of the action of drugs with their associated characteristics. The role of warning of possible overdoses or of the fore-runner signs of respiratory distress make the M.