We began by making a Grignard reagent from 1-bromopropane (p 455). This acts as a nucleophile and reacts with a 3 carbon epoxide, in basic conditions. Therefore the Grignard reagent makes a carbon-carbon bond to the less substituted carbon of the epoxide (p 448). We reacted the resulting alcohol with TsCl to create a OTs group (a very good leaving group). When this is reacted with a strong, bulky base, an E2 reaction takes place in which the Hoffman produce dominates, making 1-hexene (p 425). We can then add Br2 to the double bond to make 1,2-dibromohexane (p 172). When reacted with a strong base such as –NH2, two E2 reactions will take place, creating a triple bond between the carbons that formally contained bromine leaving groups. The triple bond is then reacted with NaNH2, which removes a hydrogen from the primary triple bonded carbon to create a acetylide ion. This ion can then react as a nucleophile with bromoethane, creating a 3-octyne. To reduce the triple bond to the desired trans-double bond, we can use Na in liquid ammonia (p 251).

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