Butyl-cyclohexyl

Further insight into the E2 mechanism comes from stereochemical studies One such experiment compares the rates of elimination of the cis and trans isomers of 4 tert butyl cyclohexyl bromide... 

Write the mechanism of the acid-catalyzed cleavage of tert-butyl cyclohexyl ether to yield cyclohexanol and 2-methylpropene. 

By application of the above rules, some groups in descending order of precedence are COOH, COPh, COMe, CHO, CH(OH)2, o-tolyl, m-tolyl, p-tolyl, phenyl, C=CH, rerf-butyl, cyclohexyl, vinyl, isopropyl, benzyl, neopentyl, allyl, n-pentyl, ethyl, methyl, deuterium, and hydrogen. Thus the four groups of glyceraldehyde are arranged in the sequence OH, CHO, CH2OH, H. 

Bulky dialkylphosphines (HPR2, where R /-butyl, cyclohexyl, 1-adamantyl, 2-norbornyl, and the like) were used together with simple CO- and CN-palladacycles for cross-coupling of unactivated chloroarenes with arylboronic ligands (Pd L=1.5, K3PO4, dioxane, reflux),413 thus apparently having a similar activity as trialkylphopshines. 

R1 = Bn, C02CH3, Fmoc, Alloc R2 =2,6-dimethylphenyl, f-Butyl, Cyclohexyl... 

Equivalent amounts of aldehydes and alkoxytrimethylsilanes react to form unsymmetrical ethers in near quantitative yields in the presence of either trimethylsilane or triethylsilane and catalytic amounts (ca. 10 mol%) of TMSI in dichloromethane.329,333,334,341 The procedure is particularly convenient experimentally when trimethylsilane is used with TMSI because the catalyst provides its own color indicator for the reduction step (color change from deep violet to vivid red-gold) and the only silicon-containing product following aqueous workup is the volatile hexamethyldisiloxane (bp 99-100°). It is possible to introduce trimethylsilane (bp 7°) either as a previously prepared solution in dichloromethane or by bubbling it directly into the reaction mixture. Cyclohexyloxytrimethylsilane and n-butanal react by this method to give a 93% isolated yield of n-butyl cyclohexyl ether (Eq. 183).334... 

R2 = 4-Tol, f-butyl, cyclohexyl, methyl oxalyl, 4-MeOC6H4, 4-CIC6H4, 2,4-F2C6H3... 

A number of nonnatural amino acids were resolved into individual enantiomers on 0-9-(2,6-diisopropylphenylcarbamoyl)quinine-based CSPby Peter and coworkers [48,90,113,114] after derivatization with Sanger s reagent, chloroformates (DNZ-Cl, FMOC-Cl, Z-Cl), Boc-anhydride, or acyl chlorides (DNB-Cl, Ac-Cl, Bz-Cl). For example, the four stereoisomers of P-methylphenylalanine, P-methyltyrosine, P-methyltryptophan, and P-methyl-l,2,3,4-tetrahydroisoquinoline-3-carboxylic acid could be conveniently resolved as various A-derivatives [113]. The applicability spectrum of cinchonan carbamate CSPs comprises also P-amino carboxylic acid derivatives, which were, for example, investigated by Peter et al. [114]. A common trend in terms of elution order of DNP-derivatized P-amino acids was obeyed in the latter study On the utilized quinine carbamate-based CSP, the elution order was S before R for 2-aminobutyric acid, while it was R before S for the 3-amino acids having branched R substituents such as wo-butyl, iec-butyl, tert-butyl, cyclohexyl, or phenyl residues. 

The reactions of NP with different aliphatic amines (ethyl-, n-propyl-, n-butyl-, cyclohexyl-, and benzylamines) and amino acids have... 

Oxide 1, when treated with primary amines like n-butyl-, cyclohexyl-, or benzylamine, gives trans-9,10-amino alcohols (264). These amino alcohols have been utilized for the preparation of aziridine 265 by treatment with trialkyl- or triarylphosphines.156... 

Meanwhile, lower monohydric alcohols were first made by the oxo process. These included n-propanol, n- and isobutanol and amyl alcohol. In PVC, only one of these assumed any importance -n-butanol - mainly in butyl benzyl phthalate. Dibutyl phthalate (DBP) was by this time considered too volatile for use in PVC in the U.S.(10). The so-called coesters - butyl octyl phthalate (BOP), butyl isodecyl phthalate and butyl cyclohexyl phthalate -have been on and off the market for many years but never achieved major success in the U.S. Dibutyl phthalate/DOP blends and BOP have probably been most successful in Japan. Diisobutyl phthalate is used in Brazil and other South American countries even today, because of its low cost. BOP is also offered in Europe, but as in the U.S., it has not been a major success. One reason could be the wide variability of composition from different suppliers. In fact, some BOP s were merely physical blends of DBP and DOP. 

The situation is similar with cyclic boronates, which are prepared by the following procedure. Steroid (10 pmol) and the respective substituted boric acid (10 jumol) are dissolved in ethyl acetate (1 ml) and the mixture is allowed to stand for 5 min at room temperature. Under these conditions, 17,20-diols, 20,21-diols and 17,20,21-triols are converted completely into boronates. Cyclic boronate was mainly produced from 17,21-dihydroxy-20-ketone, but side-products also appeared, the formation of which could be suppressed by adding a 10% excess of the reagent [387—389]. Different substituents on the boron atom, such as methyl, n-butyl, tert.-butyl, cyclohexyl and phenyl, are interesting from the viewpoint of GC—MS application. They are further suitable for converting isolated hydroxyl groups into TMS or acetyl derivatives. 

Pioneering work on the photochemical diastereocontrol in zeolite supercages was reported by Turro and coworkers in 1991 [48]. They investigated the diastereoselective photodecarbonylation of 2,4-diphenyl-3-pentanone (DPP) adsorbed in various cation-exchanged X and Y zeolites to find that the diastereo-selectivity of d9l- over mestf-2,3-diphenylbutane increases in the order LiX NaX < LiY NaY < KY. In 1996, Ramamurthy and coworkers reported the first example of photochemical asymmetric induction in chirally modified zeolites [49], where they employed the Norrish/Yang type II reaction of cis-4-tert-butyl-cyclohexyl aryl ketones to the corresponding cyclobutanols. Since then, a variety of asymmetric photoreactions in zeolite supercages have been reported as reviewed below. 

Each solution is contained in a 1.0-mm pathlength ceil. The markers show the position of the low-energy maxima for the cases where the isocyanide substituent is changed to n-butyl, cyclohexyl, and t-butyl. Increasing the bulk of the isocyanide substituent increases the Rh Rh separation and increases the energy of the 1bIu - 2ag transition. 

Y = n-butyl, n-propyl, n-pentyl, (l-methyl)butyl, cyclohexyl, benzyl, phenyl, (2-hydroxy)ethyl, (2-dimethylamino)ethyl... 

Hydroperoxid 1-tert.-Butyl-cyclohexyl- E13/1, 62 (H - O-OH) Nonan 4-Hydroxymethyl-5-oxo-XIII/2a, 772... 

Penten l-Ethoxy-3-hydroxy-3,4,4-trimethyl- E15/1, 230 (2-Br — enol-ether + R —Li/Keton) Peroxid tert.-Butyl-cyclohexyl-E13/1, 394 (Hg - H)... 

Amin Butyl-cyclohexyl- -Hydrochlorid El6d, 709 (N-Alkylie-rung), 910 (Imin-Red.)... 

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