Propanoll isomers

The l-chloro-2-propanol isomer represents about 85% of the chlorohydrin produced. In order to minimise the formation of dichlotide coproduct and ether, the reactant compositions are chosen such that the effluent Hquid contains 4—5 wt % propylene chlorohydrin. Under these conditions, the yield of chlorohydrin, dichloride, and ether from the reactants is reported to be 87—90, 6—9, and 2%, respectively (109,110,112). 

Analysis of reaction mixtures for 1-propanol and 2-propanol following incubation of NDPA with various rat liver fractions in the presence of an NADPH-generating system is shown in Table I ( ). Presence of microsomes leads to production of both alcohols, but there was no propanol formed with either the soluble enzyme fraction or with microsomes incubated with SKF-525A (an inhibitor of cytochrome P450-dependent oxidations). The combined yield of propanols from 280 ymoles of NDPA was 6.1 ymoles and 28.5 ymoles for the microsomal pellet and the 9000 g supernatant respectively. The difference in the ratio of 1- to 2-propanol in the two rat liver fractions may be due to differences in the chemical composition of the reaction mixtures (2) Subsequent experiments have shown that these ratios are quite reproducible. For comparison, Table I also shows formation of propanols following base catalyzed decomposition of N-propyl-N-nitrosourea. As expected (10,11), both propanol isomers were formed, the total yield in this case being almost quantitative. 

The addition of the intact alcohol occurred for ethanol with C113 and Ag+ both propanol isomers with Cu, CuJ, Ag+, Ag3, Ag4 and all butanol isomers with Q13 and Q15. The coordination of the alcohols was generally followed by addition of a second alcohol to form [M (ROI I)2 +. 

Miyata T, Tooru I, and Uragami T. Characteristics of permeation and separation of propanol isomers through polyvinyl alcohol membranes containing cyclodextrin. J Appl Polym Sci 1994 51 2007-2014. 

In stark contrast with the case of the lower alcohols, the propanol isomers exhibit far less pol5miorphism.Under equilibrium vapor pressure, the materials can be prepared within their ordered crystals and glass (amorphous) states only. The glass transition temperature of 1-propanol (1-Pr) is =98 K and its melting temperature is Tm= 148 K. 

Elshafei AA, Ehnaksoud SAA, Moussa MNH (1992) Electrocatalytic oxidation of the propanol isomers on platinum ad-atom electrodes in alkaline-medium. Z Phys Chem 177 211-223... 

Pirkle type 1-A chiral Isomers A, B, C, and Hexane/2-propanol Isomers B, C, D... 

The enantiomeric excess of 3.10c has been determined by HPLC analysis using a Daicel Chiracel OD column and eluting with a 60 / 1 (v/v) hexane(HPLC-grade) / 2-propanol(p.a.) mixture. At a flow of 1 ml per minute the rentention times for the different isomers of 3.10c were 6.3 min. (exo, major enantiomer) 7.1 min. (exo, minor enantiomer) 7.7 min. (endo, major enantiomer) 10.7 min. (endo, minor enantiomer). 

Hydrogenation gives aUyl alcohol [107-18-6] C H O, its isomer propanal [123-38-6] (20), or propanol, C H O [71-23-8] (21). With acidic mercuric salt catalysts, water adds to give acetol, hydroxyacetone, C2H 02 [116-09-6] (22). 

Fractional extraction has been used in many processes for the purification and isolation of antibiotics from antibiotic complexes or isomers. A 2-propanol—chloroform mixture and an aqueous disodium phosphate buffet solution are the solvents (243). A reciprocating-plate column is employed for the extraction process (154). 

In this process, the fine powder of lithium phosphate used as catalyst is dispersed, and propylene oxide is fed at 300°C to the reactor, and the product, ahyl alcohol, together with unreacted propylene oxide is removed by distihation (25). By-products such as acetone and propionaldehyde, which are isomers of propylene oxide, are formed, but the conversion of propylene oxide is 40% and the selectivity to ahyl alcohol reaches more than 90% (25). However, ahyl alcohol obtained by this process contains approximately 0.6% of propanol. Until 1984, ah ahyl alcohol manufacturers were using this process. Since 1985 Showa Denko K.K. has produced ahyl alcohol industriahy by a new process which they developed (6,7). This process, which was developed partiy for the purpose of producing epichlorohydrin via ahyl alcohol as the intermediate, has the potential to be the main process for production of ahyl alcohol. The reaction scheme is as fohows ... 

Conditions cited for Rh on alumina hydrogenation of MDA are much less severe, 117 °C and 760 kPA (110 psi) (26). With 550 kPa (80 psi) ammonia partial pressure present ia the hydrogenation of twice-distilled MDA employing 2-propanol solvent at 121°C and 1.3 MPa (190 psi) total pressure, the supported Rh catalyst could be extensively reused (27). Medium pressure (3.9 MPa = 566 psi) and temperature (80°C) hydrogenation usiag iridium yields low trans trans isomer MDCHA (28). Improved selectivity to aUcychc diamine from MDA has been claimed (29) for alumina-supported iridium and rhodium by iatroduciag the tertiary amines l,4-diazabicyclo[2.2.2]octane [280-57-9] and quiaucHdine [100-76-5]. 

Amyl alcohol describes any saturated aliphatic alcohol containing five carbon atoms. This class consists of three pentanols, four substituted butanols, and a disubstituted propanol, ie, eight stmctural isomers four primary, three secondary, and one tertiary alcohol. In addition, 2-pentanol,... 

Ghlorohydrination in Chlorine and Water. The hypochlotination of propylene gives two isomers 90% l-chloro-2-propanol and 10% 2-chloro-1-propanol. 

Propranalol hydrochloride (5-l-isopropylamino-3-(l-naphthyloxy)-2-propanol HCl) [4199-10-4] M 295.8, m 192°, 193-195 , [a] +25° (c 1, EtOH) pK 9.5. See preceding entry for physical properties. The is the active isomer which blocks isoprenaline tachycardia and is a (i-adrenergic blocker. [Leclerc et al. Trends Pharmacol Sci 2 18 7987 Howe and Shanks Nature 210 1336 7966.]... 

The substitution of one hydroxyl radical for a hydrogen atom in propane produces propyl alcohol, or propanol, which has several uses. Its molecular formula is C3H7OH. Propyl alcohol has a flash point of 77°F and, like all the alcohols, bums with a pale blue flame. More commonly known is the isomer of propyl alcohol, isopropyl alcohol. Since it is an isomer, it has the same molecular formula as propyl alcohol but a different structural formula. Isopropyl alcohol has a flash point of 53 F. Its ignition temperamre is 850°F, while propyl alcohol s ignition temperature is 700 F, another effect of the different stmcture. Isopropyl alcohol, or 2-propanol (its proper name) is used in the manufacture of many different chemicals, but is best known as rubbing alcohol. 

There are two possible structures (isomers) of three carbon atom alcohol. C is n-propyl alcohol (or 1-propanol), the other is isopropyl alcohol (or 2-propanol). The former, no.. ..mufaetured in large quantities is used in printing inks. The latter is manufactured in millions of tons to make propylene by a process similar to that used to convert ethylene to ethanol. The manutaclure of 2-propanol by this process initiated the petrochemical industry in the 1920s. 

An instructive example on how stereochemical features influence the stereochemical outcome of the elimination is the pyrolysis of xanthates from erythro-and t/zrco-l,2-diphenyl-l-propanol. The erythro-dlcohoX 8 is converted into fi-methylstilbene 9 only, and the threo-dlcohoX 10 is converted into the corresponding Z-isomer 11 only. These results support the assumption of a syn-elimination process through a cyclic transition state ... 

Position isomers differ in the positions of some reference atom, group or bond, e.g., CHjCHjCHjOH (n-propanol) and CH CHOHCHj (isopropanol) are isomers that differ in the location of the -OH group. 

Notable examples of general synthetic procedures in Volume 47 include the synthesis of aromatic aldehydes (from dichloro-methyl methyl ether), aliphatic aldehydes (from alkyl halides and trimethylamine oxide and by oxidation of alcohols using dimethyl sulfoxide, dicyclohexylcarbodiimide, and pyridinum trifluoro-acetate the latter method is particularly useful since the conditions are so mild), carbethoxycycloalkanones (from sodium hydride, diethyl carbonate, and the cycloalkanone), m-dialkylbenzenes (from the />-isomer by isomerization with hydrogen fluoride and boron trifluoride), and the deamination of amines (by conversion to the nitrosoamide and thermolysis to the ester). Other general methods are represented by the synthesis of 1 J-difluoroolefins (from sodium chlorodifluoroacetate, triphenyl phosphine, and an aldehyde or ketone), the nitration of aromatic rings (with ni-tronium tetrafluoroborate), the reductive methylation of aromatic nitro compounds (with formaldehyde and hydrogen), the synthesis of dialkyl ketones (from carboxylic acids and iron powder), and the preparation of 1-substituted cyclopropanols (from the condensation of a 1,3-dichloro-2-propanol derivative and ethyl-... 

We have already considered the oxidation of 1-propanol in Exercise 18-7. The second isomer,... 

Transmetalation to give l-methyl-2-propenylaluminum followed by isomerization to 2-butenyl isomers may be involved in reactions between aldehydes and 2-butenyl(tributyl)-stannane induced by aluminum(III) chloride in the presence of one mole equivalent of 2-propanol. Benzaldehyde and reactive, unhindered, aliphatic aldehydes give rise to the formation of linear homoallyl alcohols, whereas branched products are obtained with less reactive, more hindered, aldehydes66,79. 

Schmidt s (1992) investigation of students conceptions (12th grade) concerning isomerism showed that students mostly regard substances from the same material type (acids, ethers) as isomers n-propanol and isopropanol, for example, are regarded as isomers, whereas propanol and ethyl-methylether are not considered to be isomers. In contrast to Schmidt s hypotheses, the shape (rod-like, cross-shaped) of the molecules was not so important for their choice. 

Rotational equilibria of 2-carbonyl substituted thiophene and furan derivatives were calculated and show that the 2-substituent favors the anti-isomer in thiophene <96MI199>. NMR shifts of 35 alkyl 3-hydroxythiophene-2-carboxylates and 3-alkylamino-l-(3-thienyloxy)-2-propanols have been compiled and analyzed <96HC17>. 

Products were analyzed via Waters Model 515 HPLC Pump fitted with a Waters model 2410 refractive index detector. Separations was performed via an Aminex HP-87H 300mm column at 65°C using 0.005M H2SO4 as the mobile phase. Compounds calibrated for this work included xylitol, arabitol, erythritol, threitol, PG, EG, glycerol, lactate, 1-propanol, 2-propanol, ethanol, methanol, and the butanetriol isomers. Any compounds not visible by RID were not quantified in this work. 

Fig. 14A-C Chromatography of the racemic monoepoxy derivatives (I—III) of Z3,Z6,Z9-18 on chiral HPLC columns A Chiralpak AD B Chiralpak AS C Chiralcel OJ-R. The solvent system for the former two normal-phase columns is 0.1% 2-propanol in n-hexane (0.45 ml/min), and that of the third column is 15% water in MeOH (0.45 ml/min). Homo-conjugated dienes, epo3,Z6,Z9-18 H (I) and Z3,Z6,epo9-18 H (III), were detected by UV (215 nm), and Z3,epo6,Z9-18 H (II) was detected by RID. The earlier eluting isomers have a 3S,4R, 6S,7R, or 9R,10S configuration...

Materials. The 1-propanol, glycerol and anthracene were obtained from Aldrich Chemical Company and were used as received. As in a previous study,17 a commercially available bis-(4-dodecylphenyl) iodonium hexafluoroantimonate salt (UV9310C GE Silicones) was used as the initiator. In this initiator, various dodecyl isomers have been attached to the phenyl rings of the diphenyliodonium salt to impart solubility in the monomer and do not effect the reactivity of the initiator.1 All studies were performed with an order of magnitude excess of initiator relative to anthracene. 

---