2-Bromobutane (sec-butyl bromide)

(b)2-Hexanol is a secondary alcohol having two more carbon atoms than 1-bromobutane. As revealed by retrosynthetic analysis, it may be prepared by reaction of ethanal (acetaldehyde) with butylmagnesium bromide.

1-Methylpropyllithium (sec-butyllithium)

Propylmagnesium bromide 2-butanone

Lithium benzenethiolate CH3CH2CH2CH2LiButyllithium

(g)The starting material is a p-toluenesulfonate ester. p-Toluenesulfonates are similar to alkyl halides in their reactivity. Substitution occurs; a butyl group from lithium dibutylcuprate replaces p-toluenesulfonate.

Phenyl Isocyanate with 1- and 2-Butanol

14.21(a)Meparfynol is a tertiary alcohol and so can be prepared by addition of a carbanionic species to a ketone. Use the same reasoning that applies to the synthesis of alcohols from Grignard reagents. On mentally disconnecting one of the bonds to the carbon bearing the hydroxyl group we see that the addition of acetylide ion to 2-butanone will provide the target molecule.

Lithium 1-hexanolate CH3CH2CH2CH2LiButyllithium

Ethylmagnesiumhalide 3-Methylbutanal

14.18In the solutions to this problem, the Grignard reagent butylmagnesium bromide is used. In each case the use of butyllithium would be equally satisfactory.

Sodiumacetylide 2-Butanone Meparfynol (94%)

By retrosynthetically disconnecting the butyl group from the carbon that bears the hydroxyl substituent, we see that the appropriate starting ketone is 2-butanone.

O3-Hexanone XMg Butylmagnesium halide

The phenyl substituent can be introduced either cis or trans to the tert-butyl group. The two alcohols are therefore stereoisomers (diastereomers).

Propyllithium CH3CH2CH2Li 1-Butanol

14.9(b)Of the three methyl groups of 1,3,3-trimethylcyclopentene, only the one connected to the double bond can be attached by way of an organocuprate reagent. Attachment of either of

2-Hexanol Butylmagnesium halide Ethanal (acetaldehyde)

Since then it has grown to be a world class producer of chemicals, with significant production facilities in China, and distribution and sales in all major world markets.

4-Methyl-3-hexen-1-ylmagnesium halide tert-Butylmagnesium halide

The Group operates in the distribution of chemical and petroleum products, in the international trading of commodities, and in the distribution of maintenance systems.