Part 7: STRUCTURE DETERMINATION

Note that these types of questions are often the most difficult on the examination. This is because they are holistic in that they require a good understanding of the reactions and the concepts and the ability to apply those concepts. They can't be memorised, they require understanding and ability to apply. Hence they help discriminate those who truly understand from those who have memorised and will soon forget.

A schematic of the solution is shown below. The information from the question is given in black. Deductions directly from this information are given in red. Points that provide potential key information are shown in green which leads to the structures.

The logical thought pathway would be based on identifying A from it's ozonolysis products. Once A is determined, one can determine and then confirm the stereochemistry of A and D. A gives B, D gives E are which in turn gives F. There are, of course, other possible thought pathways.

Common mistakes:

• Not recognising and/or assigning the stereochemistry.
• Not recognising how the stereochemistry helped define the location of the C=C in A.
• Assigning aldedhydes as the products of ozonolysis under oxidative conditions.