Topic 17- Organic II Flashcards
What is a chiral object?
A molecule that has non-super imposable on its mirror image
What are the key features of a chiral centre
A carbon bonded to 4 different groups
Optical activity
The ability of a single isomer to rotate on the plane of plane-polarised light
What is a racemic mixture?
50/50 mix of two different isomers which will cancel each other out and become optically inactive
What intermediate takes place in Sn1
Carbocation intermediate
What intermediate takes place in Sn2
Transition state
What are the conditions for the reaction between a carbonyl compound and hydrogen cyanide
Acidic conditions
What is a test for the CH3CO group?- observations?
carbonyl with warmed alkaline iodine
-forms a pale yellow precipitate
Colour change of acidified potassium dichromate if aldehyde present
orange to green
Colour change of Fehlings solution if aldehyde present
deep blue to red
Observation for Tollens Reagent for aldehydes
colourless to silver mirror
Reducing agent for reduction of aldehyde and ketones to alcohols?
LiAlH4- Lithium Aluminium Hydride
- dry ether conditions
Colour of precipitate from Bradys reagent with carbonyl group?
orange precipitate
How to identify different carbonyl compounds from derivates of Bradys reagent?
-filtered, purified and dried
- compare melting temperatures with data booklet
Why can the reaction between HCN and a carbonyl be optically inactive?
due to the C=O bond being planar, nucleophile can attack from above and below forming a racemic mixture
