Part D Addition to a,p-Unsaturated Carbonyls

Model 11 Systems for Naming Positions on a Carbonyi Compound 

An often-used numbering system for carbonyl compounds places a 1 on the oxygen, and a 2 on the carbonyl carbon. Carbons on the chain are numbered starting with 3 as shown at right. (Note that these numbers do not correspond to the numbering system usedfor lUPAC naming.) 

Another way of naming positions on a carbonyl compound uses the Greek letters a, p, y, 5, etc. to label the carbons next to, but not part of, the carbonyl group (C=0), as shown at right. 

(E) Draw an example of an a,P-unsaturated aldehyde (an aldehyde with a double bond between the a and p carbons). 

(E) According to the 1, 2, 3, 4 numbering system for carbonyl compounds described above, where 

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