Isolation of (S)-Carvone from Caraway Seeds
Add crushed caraway seeds (25 g) to a 500 ml round-bottomed flask containing distilled or de-ionised water (250 ml). Distil this mixture by vigorous boiling but taking care not to allow solid particles to enter the condenser. Collect about 80 ml of liquid and add it to a 250 ml separating funnel. Add NaCl (5 g) and shake to dissolve. Extract the aqueous mixture with dichloromethane (2 x 20 ml) and dry the combined extracts over MgSO4. Filter the solution and evaporate the dichloromethane in a pre-weighed flask on a rotary evaporator with the water bath at room temperature. Record the mass of your product (S)-carvone. Determine the infra-red spectrum of your product. Accurately make up a solution of your carvone in chloroform (approx 0.25 g in 5 cm3) and measure its optical rotation. Repeat the optical rotation measurement with (R)-carvone.
Interpret the infra-red and work out the optical purity of your (S)-carvone Upload a pdf of a paper which quotes the optical rotation of (R)-carvone to the assessment/assignment area on Blackboard. Draw a 3D-perspective structure of (S)-carvone.