Like other strong nucleophiles, triphenylphosphine attacks and opens epoxides. The initial product (a betaine) quickly cyclizes to an oxaphosphetane that collapses to an alkene and triphenylphosphine oxide.

(b) Show how this sequence might be used to convert cis-cyclooctene to trans-cyclooctene.

(a) Outline the syntheses indicated in Solved Problem 18-2, beginning with aldehydes and alkyl halides.

(b) Both of these syntheses of 1-phenylbuta-1,3-diene form the central double bond. Show how you would synthesize this target molecule by forming the terminal double bond.

Show how Wittig reactions might be used to synthesize the following compounds. In each case, start with an alkyl halide and a ketone or an aldehyde.

(a) Ph–CH=C(CH₃)₂

(b) Ph–C(CH₃)=CH₂

Show how Wittig reactions might be used to synthesize the following compounds. In each case, start with an alkyl halide and a ketone or an aldehyde.

(c) Ph–CH=CH–CH=CH–Ph

(d)

Predict the major products of the following reactions.

(a)

Predict the major products of the following reactions.

(b)

Predict the major products of the following reactions.

(c)

Predict the major products of the following reactions.

(d)

Propose a mechanism for both parts of the Wolff–Kishner reduction of cyclohexanone: the formation of the hydrazone, and then the base-catalyzed reduction with evolution of nitrogen gas.

Propose a mechanism for both parts of the Wolff–Kishner reduction of cyclohexanone: the formation of the hydrazone, and then the base-catalyzed reduction with evolution of nitrogen gas.

Predict the major products of the following reactions:

(a)

Predict the major products of the following reactions:

(b)

Predict the major products of the following reactions:

(c)

Predict the major products of the following reactions:

(d)

Draw structures of the following derivatives.

(a) the 2,4-dinitrophenylhydrazone of benzaldehyde

Draw structures of the following derivatives.

(b) the semicarbazone of cyclobutanone

Draw structures of the following derivatives.

(c) cyclopropanone oxime

Draw structures of the following derivatives.

(d) the ethylene acetal of hexan-3-one

Draw structures of the following derivatives.

(e) acetaldehyde dimethyl acetal

Draw structures of the following derivatives.

(f) the methyl hemiacetal of formaldehyde

Draw structures of the following derivatives.

(g) the (E) isomer of the ethyl imine of propiophenone

Draw structures of the following derivatives.

(h) the hemiacetal form of 5-hydroxypentanal

Name the following ketones and aldehydes. When possible, give both a common name and an IUPAC name.

(b) CH₃(CH₂)₂CO(CH₂)₂CH₃

Name the following ketones and aldehydes. When possible, give both a common name and an IUPAC name.

(c) CH₃(CH₂)₅CHO

Name the following ketones and aldehydes. When possible, give both a common name and an IUPAC name.

(d) PhCOPh

Name the following ketones and aldehydes. When possible, give both a common name and an IUPAC name.

(g) CH₃CH₂CHBrCH₂CH(CH₃)CHO

Name the following ketones and aldehydes. When possible, give both a common name and an IUPAC name.

(h) Ph–CH=CH–CHO

Name the following ketones and aldehydes. When possible, give both a common name and an IUPAC name.

(j)

Name the following ketones and aldehydes. When possible, give both a common name and an IUPAC name.

(k)

Name the following ketones and aldehydes. When possible, give both a common name and an IUPAC name.

(l)