9. Alkenes and Alkynes

How much more stable is the most stable staggered conformer than the most stable eclipsed conformer?

Show how you would synthesize the following compounds, starting with acetylene and any compounds containing no more than four carbon atoms.

d. trans-hex-2-ene

e. 1,1-dibromohexane

f. 2,2-dibromohexane

Show how you would synthesize the following compounds, starting with acetylene and any compounds containing no more than four carbon atoms.

a. hex-1-yne

b. hex-2-yne

c. cis-hex-2-ene

Solved Problem 9-1 showed the synthesis of dec-3-yne by adding the hexyl group first, then the ethyl group. Show the reagents and intermediates involved in the other order of synthesis of dec-3-yne, by adding the ethyl group first and the hexyl group last.

Which combination of acetylide anion and alkyl chloride can be used to synthesize ${\mathrm{CH}}_3-C\equiv C-{\mathrm{CH}}_2{\mathrm{CH}}_3$ via alkynide synthesis?