Question

5 Fage 5 Which of the following dienes react faster in a Diels-Al explanation. in a Diels-Alder reaction? Give a BRIEF [3 marks) b. A number of highly conjugated organic compounds have the more widely used is 4-methylbenzylidene cam shown below. Suggest a simple synthesis of this compound condensation. Clearly indicate the starting materials and unds have found use as sunscreens. One of benzylidene camphor (4-MBC), whose structure this compound using a crossed aldol materials and reagents and conditions. Hz [3 marks) c. Outline the synthesis of the following compound usin malonic ester synthesis method. Draw the structure of intermediates, reagents and necessary conditions ates, reagents and necessary conditions to receive full credit. он lowing compound using either the acetoacetic ester or the Draw the structure of the starting material and show all ST CH [8 marks]

Answer 1

a) In Diels alder reaction generally Dienes having electron donating group are very reactive than the dienes having electron withdrowing group. Diene A has carbonyl group in the conjugation with double bond which will became less reactive. Thus B is more reactive than A.

b)

NaOH = CH - Camphor 4-Methylbenzaldehyde H3C 4-MEC Hechanism HOM HC HC

c)

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