Week 1 Orgo

Select the vibrations that should be infrared active. CH3CH2CH2C≡CCH2CH2CH3, the C≡C stretch CH3CH2CH2CH2C≡CH, the C≡C stretch trans‑3‑hexene, the C=C stretch (CH3)2C=O, the C=O stretch (CH3CH2)3C−Cl, the C−Cl stretch

(CH3)2C=O, the C=O stretch (CH3CH2)3C−Cl, the C−Cl stretch CH3CH2CH2CH2C≡CH, the C≡C stretch

Which of these structures has the most steric strain? staggered butane 1,1,3,3,5,5‑hexamethylcyclohexane 1,1‑dimethylcyclobutane

1,1,3,3,5,5‑hexamethylcyclohexane

Which of these structures has the most angle strain? 1,1‑dimethylcyclobutane staggered butane 1,1,3,3,5,5‑hexamethylcyclohexane

1,1‑dimethylcyclobutane

Which of these structures has the most torsional (eclipsing) strain? 1,1,3,3,5,5‑hexamethylcyclohexane staggered butane 1,1‑dimethylcyclobutane

1,1‑dimethylcyclobutane

What is the F-B-F bond angle?

120 degrees (trigonal planar)

Select the correct common name and/or IUPAC name for the structure: Which name(s) fit this structure? 1‑pentanoyl‑1‑fluorocyclopentane 1‑(1‑fluorocyclopentyl)‑1‑butanone or 1‑(1‑fluorocyclopentyl)butan‑1‑one 1‑fluoro‑1‑cyclopentyl‑2‑pentanone or 1‑fluoro‑1‑cyclopentylpentan‑2‑one 1‑fluoro‑1‑cyclopentylbutanone

1‑(1‑fluorocyclopentyl)‑1‑butanone or 1‑(1‑fluorocyclopentyl)butan‑1‑one

How many unique C13C13 NMR signals exist in the spectrum for the compound?

4

My Attempt How many unique C13C13 NMR signals exist in the spectrum for the compound?

8

Consider the reaction between butyllithium and ethanol. CH3CH2CH2CH2Li+CH3CH2OH⟶CH3CH2CH2CH3+LiOCH2CH3 Identify the curved arrows to explain how the product is formed. - A curved arrow starts from the C−CH2Li bond and points to the hydrogen on ethanol. -A curved arrow starts from the C−Li bond and points to the hydrogen on ethanol. -A curved arrow starts from the O−H bond and points towards the oxygen. -A curved arrow starts from the C−Li bond and points to the carbon.

A curved arrow starts from the C−Li bond and points to the hydrogen on ethanol. A curved arrow starts from the O−H bond and points towards the oxygen.

Which structure(s) contain a plane of symmetry? Which molecule is chiral?

A,C B

Both aldehydes and ketones contain carbonyl groups. In aldehydes, the carbonyl carbon atom is bonded to a hydrogen atom, whereas in ketones, the carbonyl carbon atom is bonded to another carbon atom. Select the true statements about aldehydes and ketones. Aldehydes contain a carbon-oxygen double bond. Both aldehydes and ketones can hydrogen bond with water molecules. Ketones have lower boiling points than alcohols of similar size. Aldehydes with more than five carbon atoms are soluble in water, but not organic solvents. Propanal is a gas at room temperature, whereas formaldehyde (methanal) is a liquid at room temperature. Butanal has a higher boiling point than 2-butanol.

Aldehydes contain a carbon-oxygen double bond. Both aldehydes and ketones can hydrogen bond with water molecules. Ketones have lower boiling points than alcohols of similar size.

Consider the reaction between butyllithium and ethanol. Identify each reactant in this reaction as a Brønsted acid or base. CH3CH2CH2CH2Li+CH3CH2OH⟶CH3CH2CH2CH3+LiOCH2CH3 Butyllithium is a......... Ethanol is a......

Butyllithium is a bronstead basse Ethanol is a bronstead acid

Write the condensed notation for the amide.

CH3CH2CH2CH2CH2CH2CONH2

Write the condensed notation for the amide.

CH3CH2CH2CON(CH3)CH2CH3

Write the condensed notation for the amide.

CH3CH2CON(CH3)2

Arrange the compounds in order of decreasing pKa, highest first. CH3CH2SH, CH3CH2OH, ClCH2CH2SH

CH3CH2OH < CH3CH2SH < ClCH2CH2SH

Rank these bases in order of increasing base strength.

II<I<III

Identify the reactant, reagent, and solvent to synthesize the Grignard reagent.

Reactant - iPrCl Reagent - Mg Solvent - CH3CH2OCH2CH3

Select the reagents needed to effect the transformation from the carboxylic acid to the aldehyde. Draw the structure of the product 1.

SOCl2 LiAlH(OtBu)

Consider the stereochemistry of the compound and its relation to optical activity. Which statement is true? The compound is optically active. The optical activity cannot be determined by looking at the structure alone. The compound is optically inactive.

The compound is optically inactive

What is the relationship? They are chair conformations of the same molecule, and they are conformational enantiomers. They are different molecules, and they are diastereomers. They are different molecules, and they are enantiomers. They are chair conformations of the same molecule, and they are conformational diastereomers. They are identical conformations of the same molecule.

They are identical conformations of the same molecule.

Which of the groups are present in acetyl‑CoA? Select five groups.

amido, imidazole-like, phosphoanhydride, phosphoryl, thioester

The magnesium‑bound carbon of a Grignard reagent reacts as if it is a carbanion. radical. carbocation.

carbanioin

Select the atoms or ions drawn with valid Lewis dot structures.

carbon 4 dots, oxygen 6 dots

Draw the organic intermediate of the reaction scheme and choose the appropriate reagents to perform the transformations.

culi nabh4

Translate line‑bond notation to Newman projection. This Newman Projection is....

eclipsed

The molecule BF3 is.......

nonpolar - 3 flourines are equally spread apart

Which properties would you expect to be different for the two enantiomers of 2‑pentanol? optical rotation solubility in hexane density boiling point taste (Hint: Your taste buds are chiral.) solubility in (𝑆S)‑3‑methylhexane dipole moment

optical rotation taste solubility in (S)-3-methylhexane

The B-F bond in BF3 is....

polar

This carbon atom is a...... strong base weak acid strong acid weak base strong base and also an excellent..... nucleophile leaving group electrophile.

strong base nucleophile

What is the molecular shape of BF3?

trigonal planar

Predict the molecular shape of the sulfite ion.

trigonal pyramidal - 1 lone pair