Question

Using any necessary inorganic reagents, show how you would convert acetylene and isobutylbromide to

(a)meso-2,7-dimethyloctane-4,5-diol,(CH₃)₂CHCH₂CH(OH)CH(OH)CH₂CH(CH₃)₂ .

(b) (± ) -2,7-dimethyloctane-4,5-diol

Short answer

_{Reagents are compounds incorporated into a system to bring about a chemical reaction. Some examples of reagents include Collins reagent and Grignard reacgent.}

Step-by-step solution

Reagents

_{Reagents are compounds incorporated into a system to bring about a chemical reaction. Some examples of reagents include Collins reagent and Grignard reacgent.}

Alkene Dihydroxylation

Alkene dihydroxilation constitutes a process that transforms an alkene to a vicinal diol. A transition metal possessing a high oxidation state like osmium or manganese are used in this oxidation reaction.

Conversion of acetylene and isobutylbromide to different compounds

Diols are produced by the different reactions like the syn-dihydroxylation with O_SO₄or cold KMnO₄ . It can also be done via the anti-hydroxylation via an epoxide using peroxyacid and water. The problem utilized inorganic reagents, hence we requireO_SO₄ reagent than the peroxyacid that is organic.

(a)Part (a) needs the synthesis of meso isomer, hence, syn-addition happens on the cis-alkene.

The alkene must be cis to create a meso product from the syn addition. Hence, reduction is performed with Lindlar’s catalyst to generate the cis alkene.

(b)The alkene created must be trans to generate a(± ) product from the syn addition. Hence, reduction is done using Na/NH₃ .