3- Pentanol derivatives

The observation that fram-2-hydroxy-l-cyclopentanecarboxamide does not react with aldehydes or ketones was used in the synthesis of stereohomo-geneous cis cyclopentane-fused oxazinones and c -2-aminomethyl-l-cyclo-pentanol derivatives. The cumbersome separation of the cis- and tram-2-hydroxy-l-cyclopentanecarboxamides can be avoided, because only the cis isomer forms the oxazinone ring (81S628 83T1829). 

In addition to the ring expansion of cyclobutane derivatives, 1-cyclopentylcyclo-pentanol derivatives and spiro compounds (Scheme 9.41) could be utilized in the iron-initiated transformation utilizing anhydrous iron(III) chloride on silica, with good yields [99]. 

Diastereoselective exchange of iodine for hydrogen has been effected by reaction of O-protected l,l-diiodo-4-methyl-3-pentanol derivatives 51 with dialkylmagnesium or alkyl... 

The addition of phosgene to l,2-epoxy-2,4,4-trimethylpentane did not result in the formation a chloroformate, but instead proceeded with the formation of pentene and pentanol derivatives [1052] ... 

Squamulosone (77) was treated in the fungus M. plumbeus ATCC 4740 to give not only cyclo-pentanol derivatives (89, 90) but also C12 hydroxylated products (91-93) (Collins et al., 2002b) (Figure 20.31). 

The model was tested by the micellar liquid chromatography separ ation of the five rarbornicin derivatives and four ethers of hydroxybenzoic acid. Micellar mobile phases were made with the sodium dodecylsulfate and 1-pentanol or isopentanol as modifier. In all cases the negative signs of the coefficients x and y indicate that at transition of the sorbat from the mobile on the stationar y phase the number of surfactant monomers as well as the number of modifier molecules increases in its microenvironment. 

The reaction of lead tetraacetate (LTA) with monohydric alcohols produces functionalization at a remote site yielding derivatives of tetrahydrofuran (THF) 12). An example is the reaction of 1-pentanol with LTA in nonpolar solvents which produces 30% THF. The reaction, which is believed to proceed through free-radical intermediates, gives a variable distribution of oxidation products depending on solvent polarity, temperature, reaction time, reagent ratios, and potential angle strain in the product. 

A simulated moving bed system has been proposed for the production of p-cresol from mixtures of cresol isomers even derived from coal tar [52]. Neuzil et al. give details of the development of the adsorbent and desorbent system reviewing balancing mass transfer issues with selechvity [53]. The desorbent for the cresol system is 1-pentanol. For these Hquid adsorptive systems where highly polar molecules are adsorbed and desorbed with polar desorbents, the tolerance of the system for trace polar contaminants is higher because the feed and desorbent can more easily exchange with them on the surface of the zeolites. 

Alkylaminotetrahydropyrans may be considered derivatives of aldehydes. They are reductively cleaved by lithium aluminum hydride to amino alcohols. Thus 2-(iV-piperidyl)tetrahydropyran afforded, after refluxing for 2 hours with 2 mol of lithium aluminum hydride in ether, 5-piperidino-l-pentanol in 82% yield [507]. 

Tab. 10.8 summarizes the application of rhodium-catalyzed allylic etherification to a variety of racemic secondary allylic carbonates, using the copper(I) alkoxide derived from 2,4-dimethyl-3-pentanol vide intro). Although the allyhc etherification is tolerant of linear alkyl substituents (entries 1-4), branched derivatives proved more challenging in terms of selectivity and turnover, the y-position being the first point at which branching does not appear to interfere with the substitution (entry 5). The allylic etherification also proved feasible for hydroxymethyl, alkene, and aryl substituents, albeit with lower selectivity (entries 6-9). This transformation is remarkably tolerant, given that the classical alkylation of a hindered metal alkoxide with a secondary alkyl halide would undoubtedly lead to elimination. Hence, regioselective rhodium-catalyzed allylic etherification with a secondary copper(l) alkoxide provides an important method for the synthesis of allylic ethers. 

The 0x0 process is used to convert the C4 fraction to C5 derivatives. Synthesis gas is catalytically reacted with 1-butene to give pentanal which can be hydrogenated to 1-pentanol ( -amyl alcohol), giving a route to C5 compounds in larger amounts than what would be available from C5 alkanes in petroleum. 

The behavior of the Cd(II)/Cd(Hg) system in the absence and presence of n-pentanol in noncomplexing media was analyzed using reciprocal derivative and double derivative chronoamperome-try with programmed current (RDCP and RDDCP respectively) [54]. The RDCP and RDDCP are very versatile in the determination of kinetic parameters of electrode processes. 

L. Colombo et al.110) synthesized two related (S)-proline derivatives and used them as chiral ligands for lithium in reactions of n-butyllithium with benzaldehyde. 1-Phenyl-1-pentanol was obtained with moderate optical purity (4-33% e.e.). Both nitrogen atoms as well as the free hydroxy group in ligands (91) to (94) appear to be essential centers for coordination with the alkali metal. 

The chemical reduction of 4,7-phenanthroline has been re-examined. With tin and hydrochloric acid, l,2,3,4-tetrahydro-4,7-phenanthroline predominates over the 1,2,3,4,7,8,9,10-octahydro derivative, whereas with sodium in pentanol the octahydro derivative is the principal product.246 In the course of the structural verification of these products, it has been found246 that the compound previously thought247 to be 3,8-dioxo-l,2,3,4,7,8,9,10-octahydro-4,7-phenanthroline (49) is in fact the linear diazaanthracene isomer (50) and the derived octahydro compound reported by Smith and Yu248 is likewise a diazaanthracene derivative. 

For example, treatment of esters 819-21 with hydrazine in refluxing ethanol gave the N-unsubstituted bicycles 9 (R1 = H). 1-Methyl derivatives (9 R1 = Me) were also prepared.22 The hydrazine 11, obtained from the acid 10a, was heated at reflux without puriiication in dilute acid to give 12 (R = H). The acid chloride 10b furnished hydrazide intermediates 10c,17,23,24 which were cyclized by fusing the solid,23 refluxing with pyridine in the presence of copper powder,24 or by heating with potassium carbonate in 1-pentanol.17... 

In many cases it is advantageous to remove the hydrolyzed reagent, DNP-OH, from the reaction mixture in order to prevent its interference during chromatography with amino acid derivatives which are soluble in diethyl ether. This may be accomplished by dissolving the crude DNP derivatives in 91% sulfuric acid and extracting the DNP-OH with benzene. The acid solution is then diluted at 0 °C to 30% sulfuric acid and extracted with 10% tert.-pentanol in benzene for recovery of the DNP-amino acids. DNP-OH may also be removed by sublimation [ 11 ], or by column chromatography on silica gel [ 12] or alumina [13]. 

After converting 2-pentanol to its bromo derivative, a solution of the Grignard reagent is prepared. 

Polysaccharide-based CSPs also exhibit a chiral recognition for alcohols and a large number of resolutions have been reported. Chiral alcohols can usually be directly resolved with hexane containing a small amount of an alcohol as the eluent. For aliphatic alcohols, which cannot be directly resolved, their resolution is often efficiently attained as phenylcarbamate or benzoate derivatives on OD (Figure 17).85 For example, 2-butanol and 2-pentanol are completely resolved with a very high selectivity on OD as their phenylcarbamates. The derivatization of alcohols to phenylcarbamates and benzoates can be easily achieved by the reaction with phenyl isocyanates and benzoyl chlorides, respectively. In most cases, the phenylcarbamates are better resolved than the benzoates. For chiral compounds bearing phenolic hydroxy groups, the addition of a small amount of an acid to an eluent is recommended to depress its dissociation. 

A series of alcohols (C4 - Cll) were identified in the tail meat. Odor threshold concentrations were generally higher for alcohols than the aldehyde counterparts. Except for 1-pentanol, the remainder of alcohol peaks were very small and might not be significant in overall arctna of boiled crayfish tail meat. Josephson et al. (23-25) found l-octen-3-ol, an enzymatic reaction product derived from lipids, to be one of the volatile ccxnponents widely distributed in fresh and saltwater fish. The compound 2-butoxyethanol identified in crayfish tail meat (3) has been reported in beef products (26-27). GC aroma perception of standard 2-butoxyethanol gave a spicy and woody note, hence this compound could be an important flavor component of the boiled crayfish tail meat. 

The key starting compound is the mono nitro derivative of calix[4]arene 4, which was obtained via a single-step reaction with 10 equivalents of 63% HNO3 in a mixture of dichloromethane and glacial acetic acid in less than 5 min in 94% yield according to the literature method. Compound 4 converted to bisphthalonitrile derivative 5 by the given method in 59% yield. Ball-type ZnPc 6 was prepared from 5 and zinc acetate in 1-pentanol in the presence of DBU. Hexanuclear ball-type ZnPc 8 was obtained by the reaction of 6 with 7 in a mixture of NaOH, MeOH, THF, and activated zinc powder with a yield of 55%. 

Condensation of formaldehyde with cyclopentanone yields a compound with four -CH2OH groups, which can be nitrated to the tetra-nitrate. Analogous derivatives of hexanone, hexanol, and pentanol can be prepared in the same manner, but in the case of pentanol and hexanone the fifth hydroxyl group also becomes esterified ... 

Figure 6. Capillary GC-separation of R-(+)-derivatives of secondary alcohols and their esters, isolated by preparative GC from yellow and purple passion fruits (DB 210, 30 m/0.33 mm i.d., 140 °C, pentanol-2 OV 101, 50 m/0.33 mm i.d., 170 °C, heptanol-2).

Recovered polystyrene derivative on SCW treatment of UP2 at 300°C in the presence of 5-amino-1-pentanol was dissolved in chloroform, added triethylamine and MA, and heated at 50°C for 24 h. Resulting solid was purified by reprecipitation and dissolved in St. After the addition of AIBN, the St solution was degassed and heated at 60°C for 3 h. 

When 5-amino-1-pentanol was used as an additive, amino groups reacted prior to hydroxy groups, leading to the formation of a polystyrene derivative with side-chains having terminal hydroxy groups. The hydroxy groups could be modified with MA, and polymerized with styrene to afford a network polymer again. 

Secondary chlorides of propane and butane can be made without side reactions from isopropyl alcohol and s-butyl alcohol by treatment with HCl and ZnCl, in the cold however, treatment of the next higher homolpg 3-pentanol under the same conditions gives a mixture of chloropentanes. The 2- and 3-chloropentanes are best obtained by the SOClj-pyridine procedure. The corresponding bromo derivatives have been obtained using hydrogen bromide at a low temperature however, care must be taken to avoid isomerization. 

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