Retrosynthetic analysis is the process of working backward to develop the synthesis of a new compound. In Chapter 10, we begin developing multistep syntheses in this manner. For now, try to work backward a single step by suggesting an alkene and a reagent that would give products (a)–(i). [Your answers should not include alkenes that undergo rearrangement to give the desired products.]

(a)

The two butenedioic acids are called fumaric acid (trans) and maleic acid (cis). 2,3-Dihydroxybutanedioic acid is called tartaric acid.

Show how you would convert

a. fumaric acid to (±)-tartaric acid.

b. fumaric acid to meso-tartaric acid.

Devise a synthesis for each compound, starting with methylenecyclohexane and any other reagents you need.

c. 1-(hydroxymethyl)cyclohexanol

What stereoisomers are obtained from the reaction of each of the following alkenes with OsO₄ followed by aqueous H₂O₂?

a. trans-2-butene

b. cis-2-butene

Synthesize the following molecules beginning with only organic molecules containing three carbons or fewer.

(f)

Show how you would accomplish the following conversions.

c. trans-hex-3-ene to meso-hexane-3,4-diol

Predict the major products of the following reactions, including stereochemistry where appropriate.

(k) cyclopentanol + H₂SO₄/heat

(l) product from (k) + OsO₄/H₂O₂, then HIO₄

(m) sodium ethoxide + 1-bromobutane

Predict the product(s) of each of the following reactions, making sure to indicate the relative stereochemical outcome. Indicate any racemic mixtures by drawing both enantiomers.

(c)