1-decanol, reaction

Several procedures are used to control the ratios of cyclodextrins produced. One is addition of a substance to the reaction mixture that can gready affect the formation of one specific cyclodextrin over another. For example, in the presence of 1-decanol and 1-nonanol, a-cyclodextrin is produced almost exclusively whereas hexane or toluene promote the production of P-cyclodextrin. Conversely both cyclodextrins are produced simultaneously in the presence of 1-heptanol (2,4). 

In 1899 R. C. Guerbet discovered the self-condensation reaction of alcohols, which, via the aldehyde as an intermediate, lead to branched structures (2-alkyl alcohols) (Fig. 4.21) - the Guerbet alcohols. Starting with fatty alcohols from vegetable sources, such as octanol and decanol, the corresponding C1(, and C2o alcohols are produced (2-hexyldecanol and 2-octyldecanol, respectively). The reaction is carried out under alkali catalysis and high temperatures (>200 °C). Over the years, both products have proven to be efficient emollients, but are also used for other applications, such as plasticizers or components for lubricants (Fig. 4.21). 

An example of this type reaction is the conversion of 1-decanol (CH3(CH2)gCH20H) to decanoic acid (CH3(CH2)gCOOH). 

The synthesis of the amino alcohol (5S,6S)-6-amino-5-decanol begins with reaction of the 1-chloropentylboronic ester (Section 1.1.2.1.3.1.) with sodium azide under phase-transfer conditions to form the a-azido boronic ester, which yields the a-chloro- -azidoalkyl boronic ester (1) [yield 92 % 95 % de] with (dichloromethyl)lithium under the usual conditions. The reaction of 1 with butylmagnesium chloride is unusual in that it requires zinc chloride in order to accomplish the replacement of chlorine by butyl to form /J-azidoalkyl boronic ester 2 without boron-azide /1-elimination. Standard peroxidic deboronation and reduction of the azide complete the synthesis15. 

Glucose at different concentrations was added to the reaction mixture to determine AO activity. The activity of AO from strain YR-1 using 0.5 mM decanol (final concentration) as substrate was assayed as described in Materials and Methods. The values given are the mean of two independent experiments with triplicate determinations in each case. 

By using water-soluble organic solvents, usually referred to as precipitants, the reaction can be directed to produce only one cyclodextrin. In the presence of toluene, the enzyme from B. macerans produces only (3-cyclodextrin and linear starch chains. Beta-cyclodextrin can be separated from the soluble starch chains and recovered as a precipitated toluene complex. In the presence of decanol, a-cyclodextrin is the only cyclodextrin produced using the enzyme from B. macerans.21,22 Precipitants such as large cyclic compounds similar to musk oil23 or a-naphthol and methyl ethyl ketone (butanone)24 can be used to produce 8-cyclodextrin. 

Alpha-cyclodextrin can also be produced using an organic precipitant.21,22 In the presence of decanol, the enzyme from B. macerans produces predominantly a-cyclodextrin. In the early stages of the reaction, a mixture of a- and (3-cyclodextrins are present, so the reaction must be allowed to proceed long enough for the (3-cyclodextrin to disappear. Choice of enzyme and precipitant is important. Some precipitants, such as cyclohexane, will produce a mixture of a- and (3-cyclodextrins by controlling the temperature, relative proportions of each can be controlled.32 As the temperature is increased, the relative amount of (3-cyclodextrin increases. 

This monophasic biotransformation system was used for the hydroxylation of 2,2 -dihydroxybiphenyl to 2,2, 3-trihydroxybiphenyI within a reaction time of 2.5 h and 2.2. 3,3 -tetrahydroxybiphenyl after 23 h. A mean volume productivity of 0.43 and 0.05 g l-1 h 1, respectively, was achieved for these biotransformations. Furthermore, HbpA and FDH were applied in 80 vol.% decanol to hydroxylate 2-hydroxybiphenyl to 2,3-dihydroxybiphenyl with a productivity of 0.46 g 1 1 h 1 and a total turnover number of 503. In 10 vol.% aqueous methanol the total turnover number of 30 and enzyme stability for at least 60 h were observed. Because of the... 

Typical results for the benzylation of 1-decanol in hexane are shown in Table I. Although an insoluble base such as K2CO3 was ineffective for the reaction, alkali metal cation-exchanged Y-type zeolites efficiently induced the reaction, and the highest yield (73%) was obtained when KY was used. The... 

Reaction of l-decanol(l mmol) with benzyl chloride (I mmol) in the presence of a promoter in 5 ml of hexane was performed under reflux for 5 h. 

Similar results are obtained with copper permanganate octahydrate, Cu(Mn04)2 8H20. Addition of this salt to a solution of 2-decanol in di-chloromethane results in an exothermic reaction and boiling of the mixture for 5 min. After 10 additional minutes at room temperature, 2-decanone is isolated in 93% yield [894. Allylic alcohols are oxidized in 84-85% yields to a, 3-unsaturated ketones after boiling in dichloromethane for 24 h [894]. 

In continuous-flow, liquid phase runs, high conversions of 1-decene to mixtures of decylbenzene isomers occurred in reaction with benzene over REX catalyst (Fig. 25). In analogous benzene alkylation attempts with 1-decene or 1-decanol at atmospheric pressure, side reactions of... 

Reduced prior to the sulfating reaction 2. N-Sulfates of several substituted phenyl hydroxylamlnes were also synthesized 3. ( ) Indicates that S-labeled sulfate conjugates were prepared 4. Secondary pentanol, octanol, nonanol, decanol, tetra-decanol 5. Product 4-hydroxy-2-nltrophenyleulfate. 

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