68930-33-6Relevant academic research and scientific papers
Surface-Mediated Reactions. 6. Effects of Silica Gel and Alumina on Acid-Catalyzed Reactions
Kropp, Paul J.,Breton, Gary W.,Craig, Stephen L.,Crawford, Scott D.,Durland, William F.,et al.
, p. 4146 - 4152 (2007/10/02)
Absorption of a variety of acids to chromatographic silica gel results in substantial enhancement of their catalytic activity-affording easily prepared, environmentally benign heterogeneous acids that are highly effective in mediating a number of processes.This was shown for the isomerization of allene 1 and dimerization of the corresponding 1,3-diene 2; cyclization of (R)-citronellal (5), the related diester 10, and 1,5-cyclooctadiene (15); Rupe rearrangement of alkynol 18; and Friedel-Crafts cyclodehydration of alcohols 21.By contrast, commercially available Nafion-H was significantly less effective as a heterogeneous acid catalyst.Chromatographic alumina displayed enigmatic behavior, showing enhanced acidity on the adsorption of HCl but little or no acidity on the adsorption of a variety of other types of acid.The results are discussed in terms of the surface structures of silica gel and alumina.
SELF-CONDENSATION OF ALLYLIC ALCOHOLS MEDIATED BY TiCl4
Idrissi, Mostafa El,Santelli, Maurice
, p. 1531 - 1534 (2007/10/02)
Addition of Grignard reagents to enones associated with TiCl4 leads to dehydration and Diels-Alder-like reaction giving dimeric hydrocarbons in good yields.
Lewis Acid Catalysed Addition Reactions of 1,3-Alkyl Substituted Allyl Chlorides with Alkenes
Mayr, Herbert,Klein, Herbert,Kolberg, Gerlinde
, p. 2555 - 2579 (2007/10/02)
The zinc chloride-ether catalysed reactions of 2-unsubstituted allyl chlorides (5) with alkenes (6) yield linear addition products (7) which may undergo two types of sequential reactions: Electrophilic additions to alkenes (allyl chloride induced polymeri
CATALYSIS OF THE DIELS-ALDER REACTION IN THE PRESENCE OF CLAYS
Laszlo, Pierre,Lucchetti, Jean
, p. 1567 - 1570 (2007/10/02)
FeIII- doped K10 montmorillonite combined with 4-t-butylphenol (10 mol percent) is a potent catalytic system for unactivated dienophiles.
Hindered Rotation of the Isopropenyl Group in Substituted Isopropenylcyclohexanes and Identification of Preferred Rotamers by Nuclear Magnetic Resonance. Bent Bonds May Better Bonds
Hoffmann, H. M. R.,Giguere, Raymond J.,Pauluth, Detlef,Hofer, Edgar
, p. 1155 - 1159 (2007/10/02)
The series of 2,2,6,6-tetramethyl-1-isopropenylcyclohexenes 2-6 shows hindered rotation of the isopropenyl group, the activation barrier ΔG(excit.) varying from 12.8 to >15.7 kcal/mol.Splitting patterns and chemical shifts of the olefinic protons of the i
Homologues of Monocyclic Monoterpenes. Tetramethylated Derivatives of Carvone, Carveol, β-Terpineol, Sobrerol, and Related Compounds
Giguere, Raymond J.,Ilsemann, Godard von,Hoffmann, H. M. R.
, p. 4948 - 4954 (2007/10/02)
Epoxidation of tetramethyllimonene (1) gave monoepoxide 2t, which was opened regioselectively to endo and exo tetramethylated trans-carveols 3t and 5t, respectively.The alcohols were further oxidized to tetramethylcarvone (4) and its unstable exocyclic is
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)
Hoffmann, H. M. R.,Vathke-Ernst, Heidrun
, p. 1182 - 1186 (2007/10/02)
2,4-Dimethyl-3-penten-2-ol (1) wurde in einer Mischung von waessriger Sulfonsaeure/Pentan bei Raumtemperatur geruehrt.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-oxabicycloheptan) umgewandelt.
