In: Chemistry
How many of the following responses are true?
1. A primary alkyl halide will tend to react through an SN2
mechanism because there is little hindrance to backside attack and
a primary carbocation is not very stable
2. 3-bromo-3-methylpentane will undergo substitution through an SN2
mechanism
3. If R-2-bromopentane is allowed to react with OH- the product
will be S-2-pentanol
4. SN1 leads to a racemization of sterechemistry due to the
nucleophile attacking from the backside and the leaving group
leaving
5. SN2 leads to a racemization of sterechemistry due to the
nucleophile attacking from the backside and the leaving group
leaving
I thought 1, 3, and 4 were right, but my answer was wrong! Please
help!
1. A primary alkyl halide will tend to react through an SN2
mechanism because there is little hindrance to backside attack and
a primary carbocation is not very stable
(True)
2. 3-bromo-3-methylpentane will undergo substitution through an SN2
mechanism. (False, it is a tertiary halide, it will preffer
SN1 reaction as it will form stable carbocation
intermediate).
3. If R-2-bromopentane is allowed to react with OH- the product
will be S-2-pentanol. (True, through SN2
reaction)
4. SN1 leads to a racemization of sterechemistry due to the
nucleophile attacking from the backside and the leaving group
leaving. (False, in SN1 reaction, a plainer carbocation
intermediate is formed due to sp2 hybridization of positively
charged carbon and this allow the attack of nucleophile either from
top or bottom of plaine carbocation which causes the
racenization).
5. SN2 leads to a racemization of sterechemistry due to the
nucleophile attacking from the backside and the leaving group
leaving. (False, SN2 causes inversion of configuration
called as Walden inversion not racemization).