1,3-bis(diarylmethylidene)-2-methylidenecyclohexanes in cycloaddition and cyclodimerization reactions. The role of stereoelectronic factors.
Cycloaddition and cyclodimerization reactions of 1,3-dibenzylidene- and 1,3-bis(p-methoxybenzylidene)-2-methylidenecyclohexanes, i.e., the diaryltrienes with fixed S-cis-configurations of exocyclic double bonds are studied. These compounds undergo in situ cyclodimerization of the [4 + 2]-type upon dehydration of the precursor tertiary alcohols and form endo-adducts in the Diels-Alder reaction with N-phenylmaleimide. In the presence of CF3COOH, acid-catalyzed cyclodimerization takes place leading to methylidene-substituted spirocyclodimers, which undergo intramolecular cyclization upon prolonged contact with CF3COOH to form a fused carbocyclic system containing a central, 'three-petal' fragment of six-membered rings.
Cycloadditions of allyl cations, 25. Acid catalyzed dehydrative cyclodimerization of 2,4‐dimethyl‐3‐penten‐2‐ol in two phases. Biomimetic one‐pot preparation of 3,3,5,5‐tetramethyllimonene (4‐isopropenyl‐1,3,3,5,5‐pentamethyl‐1‐cyclohexene)
Cycloadditionen von Allyl-Kationen, 25. Saurekatalysierte dehydrative Cyclodimerisierung von 2,4-Dimethyl-3-penten-2-ol in zwei Phasen. Biomimetische Eintopfdarstellung von 3,3,5,5-Tetramethyllimonen (4-Isopropenyl-1,3,3,5,5-pentamethyl-1-cyclohexen) 
 
 
 
2,4-Dimethyl-3-penten-2-ol (1) wurde in einer Mischung von wasriger Sulfonsaure/Pentan bei Raumtemperatur geruhrt. Es bildete sich 3,3,5,5-Tetramethyllimonen (2) in hoher Ausbeute. 2 wurde in sein Epoxid (3) (4-Isopropenyl-1,3,3,5,5-pentamethyl-7-oxabicyclo[4.1.0]heptan) umgewandelt.
Heat Transfer Characteristic for a New Plate Metal Hydride Reactor
The property of major metal hydride reactors in the world was analyzed and a new plate metal hydride reactor was designed.An experimental facility to test the metal hydride reactor was also designed correspondingly.The effective thermal conductivity of the plate metal hydride reactor was measured by varying the initial metal hydride packing fraction,the kind of filled gas and the pressure of the filled gas,cycle numbers.The test results show that the effective thermal conductivity of the reactor,has exceeded(7.5) W/(m·K) before activation,which is increased greatly.After alloy activation,the effective thermal conductivity of the reactor has a linear change trend with the hydrogen pressure during the interval 0.1~3.5 MPa.The effective thermal conductivity of the reactor just only decreases quickly at the beginning,but becomes stable after several cycles.