Quiz | Synthesis and Retrosynthesis Strategies

1

What is the good strategy in retrosynthetic analysis?

Work backwards (from the final product to immediate precursors …)

Count the number of carbons and determine the necessary disconnections

Check the compounds available and think about the immediate possible intermediate

All of the above

Retrosynthetic analysis: always work backwards (retrosynthetic direction). Look at the final product and find the immediate precursor(s), keeping in mind the compounds you have in your toolbox. Count the number of carbons and determine the disconnections you need

2

Which of the following conditions results in the formation of a C-C bond?

Alkyl halide + EtONa

Alcohol + CH3SOCl2

Organometallics + alcohol

Organometallics + carbonyls

Formation of carbon-carbon bond ⇒ so far we have only seen one possibility: the reaction between organometallics and carbonyls

3

How to protect an alcohol?

(CH3)3COH in acidic condition

(CH3)3COH in basic condition

Li to transform it into organometallic

PBr3 to transform it into alkyl halide

Protection: convert alcohol to ether using another alcohol in acidic condition
Deprotection: protecting group removed by an acid or a base​​​​​​​

4

What kind of compounds does CH3MgBr have to react with to form propan-1-ol?

Aldehyde

Ketone

Epoxide

Alcohol

​​​​​​​


​​​​​​​Organometallics + Alcohol → Alkane + Alkoxide

5

What is the first step in the formation of butanone from methyl lithium and propan-1-ol?

Oxidation of propanol with Na2Cr2O7

Oxidation of propanol with PCC

Protection of alcohol

Reduction of alcohol with LiAlH4

​​​​​​​

6

What is the first step in the formation of 1-methylcyclohexane-1,3-diol from methyllithium and 3-hydroxycyclohexanone?

Oxidation of alcohol with Na2Cr2O7

Oxidation of alcohol with PCC

Protection of alcohol

Reduction of ketone with LiAlH4

Without protection, an alkoxide is formed