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Mince pies, sex crimes and the synthesis of Enflurane

Dear Reader,

I have to confess I have eaten too many mince pies, the problem is that they taste too good. I am not sure of the legal status of mince pie eating in the UK. I know that some killjoys years ago banned christmas and eating mince pies, but even if the English never got around to repealing this silly law I doubt if they will have an interest in dragging me to court for the outrage of eating mince pies on christmas day.

I was also interested in the fact that Alan Turing was given a royal pardon on christmas eve, while I am pleased that this step has been taken I think that it is something which is rather late and a step which does not go far enough. To my mind a pardon is a statement saying that a person while guilty of a crime is undeserving of punishment and thus should be allowed to escape all further punishment.

For example Nixon granted a partial pardon to the war criminal William Calley, to my mind Nixon held the view that William Calley should not be punished further for his dire crime. But it is clear to the world that William Calley is still a man who committed an outragous criminal act, if you do not know what William Calley did then look up “Pinkville” or “My Lai”. While a pardon might release him from further punishment it does not remove the fact that he committed the crime nor does it say that he is not to be regarded as a blameless person.

On the other hand if we look at the Soviet Union history will see that many people who were wrongly punished have been subject to rehabilitation, to me the concept of rehabilitation includes the moral statement that includes the idea that the punishment was wrong in the first place, that the person should never have been punished and that they are now subject to a total exoneration. For example see the law in the Ukraine where it states

“The Supreme Council of Ukraine condemns hereby the repressions and dissociates itself from the terrorist methods of leadership, condoles with victims of the unfounded repressions, their relatives and kin, declares hereby its intention to steadily strive for the restoration of justice, elimination of consequences of the outrage and violations of civil rights, is intent on ensuring compensation, feasible for the time being, for the material and moral damage caused by the unlawful repression to the rehabilitated individuals and their families”

I think that a similar statement should be made the next time a new law on sexual crimes is written. All that is required is a simple single paragraph in next sexual offences or criminal justice act. I am opposed to the paragraph being used as a get rich quick scheme for people who happen to have a relative who was convicted of some truly victimless crimes, so the law should include some limits on compensation.

I hold the view that to eligible for total exoneration a person must satisfy a series of conditions

1. Their sex “crime” must be one which only involves adults (people above the age of 16 years)

2. It has to have been a “crime” which only involves consenting adults without sex being purchased or sold.

3. The “crime” had to occur in a private place

4. The “crime” has to be a violation of section 11 of the Criminal Law Amendment Act 1885.

I think that for people (living and dead) who can satisfy all four conditions should be subject to a total exoneration, and their conviction should be quashed. Now onto the chemistry.

I hold the view that being a chemist is something which can not be turned on and off at will, while feeling overfull in the evening of christmas day my mind wandered onto the synthesis of bigger and more complex fluoro compounds than the tetrafluoroethane used in air conditioning and medical products. The first one I thought of was 1,1,1,2,3,3,3-heptafluoropropane but I will save that for another day.

I was thinking of enflurane which was used for years as a replacement for halothane, this is a halogenated ether which is quite complex looking. This molecule can be disconnected back to trifluorochloroethylene, which in turn can be made from a simple freon. Here is my reterosynthesis of the compound.

Reterosynthesis of enflurane

Reterosynthesis of enflurane

Now of all the steps in the synthesis I think that the first one is the most interesting it is similar to the chemistry which makes 1,1,3,3,3-pentafluoro-2-(trifluoromethyl)prop-1-ene toxic. I also looked at the chemistry of tetrafluoroethylene, and just as I imagined it has a rich chemistry with nucleophiles. For example K. Okuhara et. al. in Bulletin of the Chemical Society of Japan, 1962, 35,  532 – 535 describes the reactions of a range of alkoxides with tetrafluoroethene.

Back to the reaction of trifluorochloroethylene, the interesting thing about this reaction is the regioselectivity of the reaction, we need to ask ourselves the question of why does the methoxy group end up on the CF2 end and not the CClF end of the molecule. I think that the reason why this happens is that the nucleophile is attracted to the higher partial positive charge which is at the end of the molecule bearing more fluorine atoms.

This electrostatic attraction effect is also seen in the nucleophilic aromatic substitution reaction, the fluorobenzenes react more quickly with nucleophiles than other halobenzenes. For example Sanger’s reagent (2,4-dinitrofluorobenzene) which is used in protein chemistry to react with amine groups is an example of a fluoroarene which is super reactive.


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