B. In each of the following pairs, circle the species that is more reactive toward nucleophilic attack. ai NH₂ OCH 3 لمند NHCH₂CH3 is VS VS VS VS VS Br CI المحمد olma OCH₂CH3

2) When conjugated aldehydes or ketones are attacked by a nucleophile, often more than one product forms. Please show resonance structures to explain which positions in the following conjugated ketone can react with NaBH4. Which product(s) can form? + H н-вн Na H CH3OH

3. Circle three allylic carbons in thiamine to the right. How many allylic hydrogens does it have? Why is the indicated carbon not allylic? N thiamine N NH₂ S -OH # allylic Hs

The following is classified as: OO H3C None of these An electrophilic substitution An electrophilic addition A nucleophilic addition CH3 A nucleophilic substitution 1. NaCN 2. H₂O H3C OH CN CH3

organic chemistry 37) The most reactive towards nucleophilic acyl substitution is:

10. Answer Rank the following molecules in order of decreasing reactivity toward nucleophilic addition. CF3 CF3 CF3 H I CF 3 F CH3 Br IV H3C II III Cl V

How the rate of the following substitution reaciton be affected if the concentraiton of bromoethane is not changed and the concentration of hydroxide is doubled? H₂ H₂ + Br H₂C OH Br H₂C The rate will be doubled The rate will increase by three times The rate will remain the same The rate will decrease to one half OH

When a nucleophile attacks a carbonyl carbon, the hybridization of the carbon atom changes from. sp² to sp² (the hybridization remains the same) sp to sp² O sp² to sp³ O sp³ to sp²

Which compound shown below would undergo nucleophilic substitution via addition/elimination the most quickly?

Which alkyl halide would be unreactive in a nucleophilic substitution reaction? Br I OI O II O III O IV OV Br IV Br II Br V Br III