DP Chemistry (last assessment 2024)
Question 18N.3.hl.TZ0.21b
| Date | November 2018 | Marks available | [Maximum mark: 2] | Reference code | 18N.3.hl.TZ0.21b |
| Level | hl | Paper | 3 | Time zone | TZ0 |
| Command term | Outline | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
18N.3.hl.TZ0.21b
Taxol is a chiral cancer drug which is synthesized using a chiral auxiliary.
(b)
Outline how chiral auxiliaries are used to synthesize the desired enantiomer.
[2]
Markscheme
chiral auxiliary creates stereochemical condition necessary to follow a certain pathway
OR
stereochemical induction
OR
existing chiral centre affects configuration of new chiral centres ✔
chiral molecule/auxiliary/optically active species is used/added/connected to the starting molecule «to force reaction to follow a certain path»
OR
«after new chiral centre created» chiral auxiliary removed «to obtain desired product» ✔
