Question 18M.3.hl.TZ2.25
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.3.hl.TZ2.25 |
| Level | hl | Paper | 3 | Time zone | TZ2 |
| Command term | Outline | Question number | 25 | Adapted from | N/A |
Taxol was originally obtained from the bark of the Pacific yew tree.
Outline how Green Chemistry has improved the process of obtaining Taxol.
[2]
Any two of:
stripping the bark kills Pacific yew tree
plant cell fermentation «and extraction»/PCF technology/use of plant cell cultures/Taxol «precursors» produced by biosynthesis/fungi/yeast/e-coli/use of natural enzymes «more sustainable process»
OR
Taxol produced semi-synthetically/Taxol from 10-DAB/10-deacetylbaccatin
uses renewable resources
OR
use «needles/leaves/twigs of» European/common yew/yew from Himalayas
«sustainable» process has eliminated «high proportion of» hazardous chemicals/waste
OR
«sustainable» process has eliminated several solvents/«sustainable» process uses greener solvents/«sustainable» process recycles/reuses solvents
OR
«sustainable» process has eliminated several «drying» steps/«sustainable» process has eliminated lots of the work-up after the synthesis
OR
«sustainable» process has increased energy efficiency
OR
«sustainable» process has no intermediates
OR
«sustainable» process uses more efficient catalysts
Accept “Pacific yew rare/slowgrowing/takes 100/200 years to mature” for M1.
Accept “synthesis of Taxol using chiral auxiliaries increases efficiency of process as single enantiomer formed” for M4.
[2 marks]
