CH 9-2: HD/IR Example (step-by-step)

CH 9-2: HD/IR Example (step-by-step)
An unknown organic compound has a formula of C4H6O.
(1) What is the Hydrogen Deficiency?
HD = _____
(2) What functional groups might be present as suggested
by the HD and formula?
(3) What functional group information can we get from the
IR spectrum:
1712 cm-1
IR spectrum = ______________
(4) Now we can refine our original ideas for the type(s) of
functional group(s) present, based on:
formula = C4H6O
Carbonyl and alkene
HD = 4
carbonyl group
Carbonyl and ring
(5) More Info: There is one 1o carbon and no 2o or 3o
carbons. Suggest one or more reasonable structures:
Note that based on this information, no rings are possible
as they would have 2o & 3o carbon atoms.