Question

1. (10 points) la. Rank the following substrates from most (1) to least reactive (4) in an SN2 reaction. Explain the reason for your choice Br ABT Chrobr 1b. Rank the following substrates from most (1) to least reactive (3) in an SNI reaction. Explain the reason for your choice lc. What is the nucleophile in the following reaction? ~ Br + CHỌCoona - OOCCH3 OOCCH + M NaBr 1d. What is the electrophile in the following reaction? Br + CH,COONa → OOCCH3 + Na le. On the following compound, label each carbon either as as primary, secondary, tertiary or quaternary carbons. BE

Answer 1

Solution=

to BE solution t. A •Br -Br BR - Bro TI IT I HBC Br 1 H BR abovec Ase SN? reaction is one step reaction in que leophile attack on the carbon atom in which leaving group is present and whon nucleophile is attack, leaving group is lekt. 1 e, the leaving group is same lie. Bre, wale It is least reactive in SAP coction, because the nucleophile can't attack the tertiary Carbon. There is steric repulsion between the three - CH3 group and nucheophile, I is most reactive because it is la primary carbon, so nue leophile attack the Carbon atom. ( X) - 1 Bur Br . Nu Nu NB Br No reaction to Nuo so order is - I ) I II

ionisation, ie it korms step is In SN reaction, the first stablised by Now, B is more reaction because it is resonance double bonds - A is least reactive, because the structure is so the reactivity order is can't worm. # I > ST 2 + CH₃cOo Na LOCOCH₃ - + NaBr Que nucleophile is chu_0° - Br + CH₃COONa ~ O COCH, NaBr ate electrophile is w ell carbon 1 c-2 (-3 is is is quaternary secondary Bre secondary tertiary tertiary Secondary ( 5 is

2. ^ trons -2-chlaro-3-hexene CH-CH TH म cis. 3, 4. dimethyl-3-heptene CH2 14- di bromocyclohexene Bur 9 E3-bromo-4-ethyl-3-octene 2 bre CH-CH39