Starting with acetylene and 1-bromobutane as the only sources of carbon atoms, show how to synthesize the following. (a) meso-5,6-Decanediol (b) racemic 5,6 -Decanediol (c) 5-Decanone (d) 5,6 -Epoxydecane (e) 5-Decanol (f) Decane (g) 6-Methyl-5-decanol (h) 6-Methyl-5-decanone

Short Answer

Expert verified
Answer: The synthesis route for meso-5,6-Decanediol from acetylene and 1-bromobutane involves the following steps: 1. Chain extension of acetylene using 1-bromobutane, forming but-3-yn-1-yl butane. 2. Hydroboration-oxidation of terminal alkyne, resulting in but-3-yn-1-yl butane-1-al. 3. Corey-Fuchs reaction to generate but-3-yn-1-yl 3-bromobut-1-yne. 4. Intramolecular nucleophilic attack, creating 5-ethynylbicyclo[4.4.0]decane. 5. Catalytic hydrogenation with a Lindlar catalyst to obtain meso-5,6-Decanediol as the final product.

Step by step solution

01

Chain extension of acetylene using 1-bromobutane

In order to form the required carbon skeleton, first extend the acetylene molecule by treating it with 1-bromobutane under the action of NaNH_2, in liquid ammonia. This will generate but-3-yn-1-yl butane, a molecule with a total of 9 carbon atoms.
02

Hydroboration-oxidation of terminal alkyne

Next, perform a hydroboration-oxidation reaction to convert the terminal alkyne group into an alcohol group. This reaction involves treating the product from step 1 with 9-BBN (borane) and then treating it with hydrogen peroxide and sodium hydroxide (NaOH). This forms the corresponding aldehyde but-3-yn-1-yl butan-1-al.
03

Corey-Fuchs reaction

To obtain the required molecule with a 10-carbon atom skeleton, carry out a Corey-Fuchs reaction on the aldehyde group. To do this, treat the product from step 2 with carbon tetrabromide (CBr_4) and triphenylphosphine (PPh_3), and then with n-butyllithium (BuLi). The resulting compound will be but-3-yn-1-yl 3-bromobut-1-yne.
04

Intramolecular nucleophilic attack

Perform an intramolecular nucleophilic attack by treating the product from step 3 with an excess of sodium amide (NaNH_2) in liquid ammonia. This will create a five-membered ring containing an alkyne group. The resulting compound will be 5-ethynylbicyclo[4.4.0]decane.
05

Catalytic hydrogenation

Finally, treat the product from step 4 with H_2 gas and a Lindlar catalyst, a process known as catalytic hydrogenation. This reaction reduces the alkyne group to a cis-alkene group in the ring. The resulting compound will be the desired meso-5,6-Decanediol, which is a cis-diol. Following these steps will allow you to synthesize meso-5,6-Decanediol from acetylene and 1-bromobutane. Similarly, by using different reaction conditions and reagents, you can synthesize the remaining target compounds from the exercise.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Draw a structural formula for the product formed by treating butanal with each reagent. (a) \(\mathrm{LiAlH}_{4}\) followed by \(\mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{NaBH}_{4}\) in \(\mathrm{CH}_{3} \mathrm{OH} / \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{H}_{2} / \mathrm{Pt}\) (d) \(\mathrm{Ag}\left(\mathrm{NH}_{3}\right)_{2}{ }^{+}\)in \(\mathrm{NH}_{3} / \mathrm{H}_{2} \mathrm{O}\) (e) \(\mathrm{H}_{2} \mathrm{CrO}_{4}\), heat (f) \(\mathrm{HOCH}_{2} \mathrm{CH}_{2} \mathrm{OH}, \mathrm{HCl}\) (g) \(\mathrm{Zn}(\mathrm{Hg}) / \mathrm{HCl}\) (h) \(\mathrm{N}_{2} \mathrm{H}_{4}, \mathrm{KOH}\) at \(250^{\circ} \mathrm{C}\) (i) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}\) (j) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NHNH}_{2}\)

All rearrangements we have discussed so far have involved generation of an electrondeficient carbon followed by a 1,2 -shift of an atom or group of atoms from an adjacent atom to the electron-deficient carbon. Rearrangements by a 1 ,2-shift can also occur following the generation of an electron-deficient oxygen. Propose a mechanism for the acid-catalyzed rearrangement of cumene hydroperoxide to phenol and acetone.

Treatment of \(\beta\)-D-glucose with methanol in the presence of an acid catalyst converts it into a mixture of two compounds called methyl glucosides (Section 25.3A). In these representations, the six-membered rings are drawn as planar hexagons. (a) Propose a mechanism for this conversion, and account for the fact that only the - \(\mathrm{OH}\) on carbon 1 is transformed into an \(-\mathrm{OCH}_{3}\) group. (b) Draw the more stable chair conformation for each product. (c) Which of the two products has the chair conformation of greater stability? Explain.

With organolithium and organomagnesium compounds, approach to the carbonyl carbon from the less hindered direction is generally preferred. Assuming this is the case, predict the structure of the major product formed by reaction of methylmagnesium bromide with 4-tertbutylcyclohexanone.

( \(R\) )-Pulegone is converted to \((R)\)-citronellic acid by addition of HCl followed by treatment with \(\mathrm{NaOH}\).

See all solutions

Recommended explanations on Chemistry Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free