Getting rid of cockroaches: For Dummies

When it comes to survival nothing can beat a cockroach. You can find them in Sub-Saharan Africa and in the cold Arctic.They survive for days without their heads and can withstand substantial amounts of radiation. When it crawls up the cabinets in your kitchen, how do you get rid of it?

This question will explore three different ways of dealing with these insects.

The first is a broad spectrum insecticide which was extracted from Chrysanthemum . It's structure is shown below:

The first step in its biosynthesis is shown below:

Two moles of the compound P react and produce Pyrophosphoric acid and compound X . It is known that X possesses a trans configuration. The reaction that P undergoes is shown below : ( PPO denotes the first bronsted base of Pyrophosphoric acid)

For a more specific attack, another compound form Haplophyton crooksii was extracted. Compound F can be thought of as a unit in the much larger extract Z . The extract's structure is shown below :

Compound F was prepared synthetically for the first time by Nobel Laureate E.J Corey . However in 2006, American researchers proposed another pathway:

It is known through high resolution mass spectroscopy that the formulae of the compounds are as follows:

• A : $C_{27}H_{34}O_{9}N_{4}$
• B : $C_{27}H_{34}O_{9}N_{2}$
• C : $C_{23}H_{28}O_{9}N_{2}$

After isolating C from a large number of by-products the scheme continues:

Again through high resolution mass spectroscopy the formulae are:

• D : $C_{22}H_{28}O_{6}N_{2}$
• E : $C_{22}H_{28}O_{5}N_{2}$
• F : $C_{22}H_{26}O_{4}N_{2}$

Here are the expansions of the chemical abbreviations:

• OTf is the triflate group.
• KHMDS is a strong base.
• Ac is the acetyl group.
• AIBN is a radical initiator.
• TEA is a solvent.

The last insecticide is probably the best and is much less harmful to the body than the others. Its structure is shown below:

If a is the number of rings in C and b is the number of double bonds in X ,

Calculate the value of $\overline{ab}$ .

BONUS

• Provide a mechanism for the transformation of B to C .
• Deduce the structure(s) of X and A - F .

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