Dicyclohexyl-methyl

Related techniques have been developed to prepare (Z-,Z)- (Z-, )- and ( -, )- dienes. Hydroboration of diacetylenes followed by protonolysis is a convenient route to (Z-,Z)-dienes, as in the conversion of 89 to 90. The requisite symmetrical diacetylenes are prepared by oxidative coupling with oxygen and cuprous chloride, as in the conversion of 1-cyclohexylethyne (78) to 89. Unsymmetrical conjugated dienes can be prepared by formation of a diacetylene ate complex, prepared from disiamylmethoxyborane by sequential reaction with different acetylides. A similar borane route to unsymmetrical diacetylenes uses dicyclohexyl methyl-thioborane. ... 

They next examined the relative reactivity profile of the bulky dicyclohexyl-methyl thioglycosides as either acceptor or donor. To this end, a-donor 83 was treated with acceptor 79b (Scheme 19). Using the mild IDCP promoter, they observed a better yield of disaccharide 85 when the acceptor had the P-configura-tion (50%) as opposed to the ot-anomer (40%). This result was attributed to the higher reactivity of the a-anomer, an observation already seen with glycosyl bromides [67]. As expected, the yield was significantly improved to 71% when the more reactive SEt donor 84 was used instead. 

C22H39BF3NO3, Cyclohexyl(hydroxy)(trifluoroacetamido(dicyclohexyl)-methyl)-borane methanol solvate, 44B, 585 C22H68B2oN202Ti, Bis(tetramethylammonium) 4,4 -commo-bis(decahydro-1, 6-dimethyl-1,6-dicarba-4-titana-closo-tridecaborate) bis(acetone), 41B, 850... 

An important application of the critical solution temperature is to the determination of the water content in such substances as methyl and ethyl alcohols. Here the system is usually the alcohol and a hydro carbon, such as -hexane or dicyclohexyl the water is, of course, insoluble in the hydrocarbon. Thus, the methyl alcohol - cyclohexane system has a C.S.T. of 45 -5° and even 0 01 per cent, of water produces a rise of 0-15° in the C.S.T. The experimental details are given below. 

For more specific analysis, chromatographic methods have been developed. Using reverse-phase columns and uv detection, hplc methods have been appHed to the analysis of nicotinic acid and nicotinamide in biological fluids such as blood and urine and in foods such as coffee and meat. Derivatization techniques have also been employed to improve sensitivity (55). For example, the reaction of nicotinic amide with DCCI (AT-dicyclohexyl-0-methoxycoumarin-4-yl)methyl isourea to yield the fluorescent coumarin ester has been reported (56). After separation on a reversed-phase column, detection limits of 10 pmol for nicotinic acid have been reported (57). 

Sturmer via the reaction of the chiral borate ester (45, 5S)-4,5-dicyclohexyl-2-isopropyloxy-1,3,2-dioxaborolane, and racemic Grignard reagent (l-methyl-2-butenyl)magnesium chloride16. A 97 3 mixture of (S)-4 and its tf-diastereomer was obtained in 89% yield. 

Z)-l-Methyl-2-butenylboronate 7 undergoes an exceptionally enantioselective reaction with benzaldehyde (99% ee), propanal (79%. 98% ee), 2-methyl-2-propenal (85%, 99% ee), and ( )-2-methyl-2-pentenal (81 %, 99% ee)10 38. Excellent enantioselectivity is also realized in reactions of the analogous chiral a-methyl-) y-disubstituted allylboronate27 40. Whether the l,2-dicyclohexyl-l,2-ethanediol auxiliary plays a beneficial role in this reaction, as suggested above for the asymmetric allylboration reactions of 6, has not yet been determined. 

Methyl-buten-(3)-in-(l) liefert mit Dicyclohexyl-boran und Deuterolyse 3-Methyl-1 -deutero-butadien-(trans-1,3) (92% d.Th.) bzw. 1-Athinyl-cyclohexen trans-2-Deute-ro-1 -[cyclohexen-(l)-yl]-athylen (87% d.Th.)3. Die Reduktionen sind auch mit [2,3-Di-methyl-butyl-(2)]-boran durchfiihrbar. 

Aus 2-Methyl-dodecadiin-(3,5) erhalt man mit zwei Mol-Aquivalenten Dicyclohexyl-boran und Protonolyse 2-Methyl-cis,cis-dodecadien-(3,5)2 (74% d.Th. Kp3 80°). (Wei-teres iiber die Reaktion s.ds. Handb., Bd. V/lb, S. 799ff.) ... 

The synthesis of new thieno-annelated 6aA4-thia-l,6-diazapentalenes 33 from iro-thiazolium-5-methyl and 5-methylene groups with dicyclohexyl amines in methanol or dimethyl sulfoxide has been achieved (Scheme 82) <1996MOL142>. 

Fig. 14.8. Chromatogram and mass spectrum showing typical GC/MS data. The mass spectrum shown was obtained from the peak indicated with the arrow. Peak identification ldecane, 2 = 1-octanol, 3 = 2,6-dimethylphenol, 4 = 2-ethylhexanoic acid, 5 = 2,3-dimethylaniline, 6 = dodecane, 7 = decanoic acid, methyl ester, 8 = dicyclohexyl amine, 9 = undecanoic acid, methyl ester, 10-dodecanoic acid, methyl ester.

The formation of certain ethers can also be accomplished with hydrogen fluoride. Anisole rather than methylphenol results from a reaction between phenol and methyl alcohol at elevated temperature (Simons and Passino, 40). The addition of an olefin to an alcohol to form an ether was shown to occur in the reaction between cyclohexene and cyclohexanol for form dicyclohexyl ether (Simons and Meunier, 66). 

Flydroformylation A catalyst solution consisting of dicarbonylacetylacetonato rhodium (I) (0.063 g) and dicyclohexyl-(3-sulfonoylphenyl)phosphine mono sodium salt (1.10 g) in n-methyl pyrrolidinone (NMP) (16.0 g) was placed in a 100 mL stainless steel autoclave at 75 C under 200 psig synthesis gas. After 15 minutes soy methyl esters (34.05 g) were added and the synthesis gas pressure raised and maintained at 400 psig for 3 hrs resulting in the desired conversion of unsaturation. 

S)-4,5-Dicyclohexyl-2-[(15,2Z)-l-methyl-2-butenyl -l,.3,2-dioxaborolane Typical Procedure21 ... 

Aliphatic primary and secondary alcohols have been found105 to react with N,N -dicyclohexyl-N-methylcarbodiimidium iodide (55), in tetrahydrofuran, benzene, or hexane at 35-50°, to give the corresponding iodides in high yields the reagent 55 is prepared by heating a mixture of N,N -dicyclohexylcarbodiimide and methyl iodide. The iodination reaction has been extended to steroidal alcohols, but attempts with carbohydrate substrates have not yet been reported. 

However, the reaction of the binuclear rj2-thioaldehyde titanocene complexes 112 (see Scheme 26) with valeronitrile, benzonitrile, and methyl thiocyanate proceeded in a similar fashion (Scheme 39).69 Related metalla-cyclic compounds were also obtained from the reactions of 112 with benzo-phenone (Scheme 39), various imines, phenyl isothiocyanate, or dicyclohexyl carbodiimide via insertion of the C = 0 and C = N bond, respectively, into the Ti-C bond.69,70... 

The above obtained [(4S)-4-Methyl-5-oxo-2-(tribromomethyl)-l,3-dioxolan-4-yl]acetic acid (102.5 mg 0.250 mmol) and 2-mercaptopyridine- N-oxide (34.4 mg 0.280 mmol) were suspended in CBrCI3 (1.5ml). The reaction mixture was heated to reflux and a solution of dicyclohexyl carbodiimide (DCC) (103 mg 0.500 mmol) in CBrCI3 (1.0 ml) was added slowly over the course of 30 min. The reaction mixture was stirred for an additional hour. The product was purified by silica gel chromatography (CH2CI2/hexanes (1 2)) and was obtained as white needles from the same solvents. Yield 72 mg (65%) mp 110-113°C. 

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