Pentanols

Colourless, volatile liquid with a strong pearlike odour, b.p. 138-5 C. Manufactured by heating amyl alcohol (1-pentanol) with potassium ethanoate and sulphuric acid or by heating amyl alcohol with ethyl ethanoate in the presence of a little sulphuric acid. Commercial... 

Fig. V-13. Composite x/ln a curve for 3-pentanol. The various data points are for different E values each curve for a given E has been shifted horizontally to give the optimum match to a reference curve for an E near the electrocapillary maximum. (From Ref. 134.)...

Giustini M ef a/1996 Microstructure and dynamics of the water-in-oil CTAB/n-pentanol/n-hexane/water microemulsions a spectroscopic and conductivity study J. Phys. Chem. 100 3190... 

This secondary amyl alcohol (2-pentanol) is a commercial product (Sharpies Solvent Corporation, etc.). 

Bromopentane. Proceed as for n-Amyl Bromide, but use 88 g. (108 ml.) of methyl n-propyl carbinol (2-pentanol), b.p. 118-5°. During the washing with concentrated hydrochloric acid, difficulty may be experienced in separating the acid layer this is overcome by adding a little water to decrease the density of the acid. Distil the purified product through a fractionating colunm some amylene passes over first, followed by the 2-bromopentane at 115-118° (120 g.). 

In addition to being regioselective alcohol dehydrations are stereoselective A stereo selective reaction is one m which a single starting material can yield two or more stereoisomeric products but gives one of them m greater amounts than any other Alcohol dehydrations tend to produce the more stable stereoisomer of an alkene Dehydration of 3 pentanol for example yields a mixture of trans 2 pentene and cis 2 pentene m which the more stable trans stereoisomer predominates... 

Dehydration of 2 2 3 4 4 pentamethyl 3 pentanol gave two alkenes A and B Ozonolysis of the lower boiling alkene A gave formaldehyde (H2C=0) and 2 2 4 4 tetramethyl 3 pentanone Ozonolysis of B gave formaldehyde and 3 3 4 4 tetramethyl 2 pentanone Identify A and B and suggest an explanation for the formation of B in the dehydration reaction... 

When optically pure 2 3 dimethyl 2 pentanol was subjected to dehydration a mixture of two alkenes was obtained Hydrogenation of this alkene mixture gave 2 3 dimethylpentane which was 50% optically pure What were the two alkenes formed in the elimination reaction and what were the relative amounts of each" ... 

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