4-Methyl-l-heptanol

Blight M. M., Wadhams L. J. and Wenham M. J. (1978) Volatiles associated with unmated Scolytus scolytus beetles on English elm differential production of a-multistriatin and 4-methyl-3-heptanol, and their activities in a laboratory bioassay. Insect Biochem. 8, 135-142. 

The higher alcohol mixture has been found to contain the following primary alcohols ra-propanol, isobutanol, 2-methyl-l-butanol, 2-methyl-1-pentanol, 2,4-dimethyl-l-pentanol, 4-methyl-l-hexanol and the following secondary alcohols isopropanol, 3-methyl-2-butanol, and 2,4-dimethyl-3-pentanol. In addition, there are definite indications of 2,4-dimethyl-1-hexanol, 4 or 5-methyl-l-heptanol, 3-pentanol, 2-pentanol, and 2-methyl-3-pOntanol. ... 

The aroma compounds studied during the biological ageing of Fino wines belong to different chemical families. The higher alcohols determined were methanol, 2-butanol, 1-propanol, isobutanol, 1-butanol, isoamyl alcohols, 1-pentanol, 3- and 4-methyl-l-pentanol, 1-hexanol, 3-ethoxy-l-propanol, Z-3-hexenol, 1-heptanol, 1-octanol, furfuryl alcohol, 2, 3-butanediol, 1-decanol, benzyl alcohol and phenethyl alcohol. 

Plant-derived compounds such as (3Z)-hexenyl acetate, (3Z)-hexen-l-ol, (2 )-hexenal, (31 )-hexenal, 4-methyl-3-heptanol, (llZ)-hexadecenal, (9Z)-hexadecenal, and (7Z)-hexadecenal are used by parasitoids to locate the host habitat (Elzen et al., 1984 Kennedy, 1984 Turlings et al., 1991 Wickremasighe and Emden, 1992). (2E)-Hexenal was strongly inhibitory to tomato seed germination at concentrations as low as 6.9 pM (Bradow and Connick, 1990). 

However, no cells in the males were keyed to the third compound (- )-cubebene which is produced by the host tree. Both sexes of 5. scolytus possess a majority of receptor cells keyed to either of the two male-produced compounds, (-)-threo-4-methyl-3-heptanol and the (-)-erythro-stereo-isomer, and in this species some cells were keyed also to (- )- -multistriatin (Wadhams et al., 1982). The relative sensitivities and specificities of these cells were determined in the same way as described for Ips species. Each cell was minimally activated by pheromone components other than its own key substance. The functional types of olfactory receptor cells discussed here for Scolytus, as with the cells of Ips, apparently are all keyed to the specific isomer of the pheromone compounds. The cells specialized to (- )-a-multistriatin are 1000 times less sensitive to the geometrical isomer d-multistriatin. However, the discrimination of the optical form of multistriatin seemed to be less pronounced. The substantially lower effect of the (-l-)-stereo-isomer (optical purity 99.5%), cannot be solely ascribed to contamination with the (- )-enantiomer. It implies that these cells in fact may also respond to (-l- )-multistriatin, although to a lesser extent. The cells keyed to methyl-heptanol are, however, highly optically specific in both species. 

Blight, M. M., Wadhams, L. J., Wenham, M. J. and King, C. J. (1979a) Field attraction of Scolytus scolytus (F.) to the enantiomers of 4-methyl-3-heptanol, the major component of the aggregation pheromone. Forestry, 52, 83-90. 

The first route attempted for the synthesis of (3J ,4S)-4-methyl-3-heptanol (33, Scheme 8.6) involved cleavage of (R,R)-2,3-butanediol from the intermediate analogous to 26, which failed, but cleavage of (R,R)-2,3-butanediol (l-chlorobutyl)boronate analogous to 25 and esterification with (S,S)-DIPED was successful. Methylation with methylmagnesium bromide yielded only (S,S)-DIPED methylboronate (29), the first evidence of sequential double diastereoselection and the stereodirected alkoxide migration described above (Scheme 8.2) [13]. 

Reversal of the order of introduction of the two alkyl groups was then tested. Starting from 29 it was straightforward to prepare DIPED (l-chloroethyl)boronate (30) and convert it into the 1-methylbutyl intermediate 31 by treatment with propylmag-nesium chloride (Scheme 8.6). (Dichloromethyl)lithium insertion and ethylation readily yielded 32, which was oxidized to (3R,4S)-4-methyl-3-heptanol (33) (99.8% di-astereopurity), which is the trail pheromone of the southeast Asian ponerine ant Lep-togenys diminuta [13]. The pheromone activity of 33 was 500 times greater than that of any of the other stereoisomers [31]. 

Non-aqueous binary glass formers were studied by Micko et They worked on mixtures of toluene with polychlorinated biphenyl or picoline (with different isotopic compositions) at low temperatures and measured, among other properties, the H spin-lattice relaxation rates. The analysis of the data allowed conclusions on glassy dynamics. Bauer et reported a related study on mixtures of alcohol isomers, 4-methyl-3-heptanol and 2-ethyl-l-hexanol, making use of H and H relaxation experiments. 

Oxa-4-azacyclohexane, see Morpholine 3-Oxa-l-butanol, see Methyl cellosolve Oxacyclopentane, see Tetrahydrofuran 3-Oxa-l-heptanol, see 2-Butoxyethanol Oxetan-2-one, see p-Propiolactone... 

Fig. 4.5 Extent of hydrolysis of glycoside of different volatile compounds during MLF with four strains of malolactic bacteria (MLB). Values are calculated as a percentage ratio between the concentration of glycosides in MLF samples and in a non-MLF control. Sum of 1-hexanol, trans- and CM-3-hexenol, trans- and c/i-2-hexenol sum of isoamyl alcohols, heptanol, and 4-hydroxy-4-methyl-2-pentanol sum of benzyl alcohol and 2-phenylethanol sum of vanillin and benzaldehyde sum of 4-vinylphenol and 4-vinylguaiacol sum of Unalool and a-terpineol sum of nerol and geraniol sum of cis- and rrani-linalool oxides (pyranic and furanic) sum of 3,7-dimethyl-l,5-octadien-3,7-diol and the two 2,7-dimethyl-2,7-octadien-l,6-diol isomers (from Ugliano and Moio 2006, reproduced with permission)...

A solution of 16.0 g a-allylbutyrophenone in 180 mL rm-butyl alcohol was irradiated under nitrogen in an immersion well with a Pyrex-filtered 450-W Hanovia mercury arc until < 10% of the starting ketone remained. GC analysis showed six products, but none of products was identified as 3-methyl-l-benzoylcyclopentane. After stripping of the solvent, the residue was chromatographed on neutral alumina with cyclohexane/CHCl3 (1 1) as the eluent to afford five components, of which the first three were further purified by GC through a column packed with 15% QF-1 and 3% Carbowax. These compounds were 1 -phenyl-3-penten-1 -one, 4-phenyl-3-ethyl-4-pentenal, 1 -phenyl-2-aUylcyclobutanol, 2-phenylbicyclo[2.2. l]heptanol-2, and 3-phenyl-4-ethyl-3-cyclopentenol. 

Draw a structure for each alcohol. (a) 3-pentanol (b) 2-methyl-l-butanol (c) 3-ethyl-2-hexanol (d) ethanol 90. Draw a structure for each alcohol. (a) 1-hexanol (b) 3,4-dimethyl-2-heptanol (c) 3-propyl-3-octanol (d) 33-diethyl-2,2-dimethyl-l-hexanol... 

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