Page 31 - Pharmd general phytochemistry I-Final2024_LEUCTERS
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2- Monocyclic monoterpene alcohols:
Menthol 2ry alcohol
Source: Peppermint oil. OH
Separation of menthol from peppermint oil (by cooling):
Cooling 3 times at different temperatures
(+15, +5, -10°C), Then centrifuge
Liquid oil Menthol crystals
(menthone + menthol)
NH2OH.HCl Oxime ether MENTHOL
O OH + menthol Dil. H2SO4
Synthesis of menthol:
OH H OH
2
Thymo
Hydrogenatio
dl-menthol
Racemic
29
