To Accompany Wade, Organic Chemistry, 4/e.
Chapter 6. Alkyl Halides: Nucleophilic Substitution and Elimination. For each of the following questions, please refer to the following article:
Blood substitute May Be Anticipated Break" by Robert Davis (USA Today, June 20, 2000)
Did you know that about every 3.7 seconds someone in America has a transfusion of two to three units(pints) of blood? This life-saving substance, the very basis of life, is needed throughout the world, while many non-emergency surgeries are postponed to later dates due to shortage in the blood supply, and while much of the donated blood is found to be tainted by such viruses as HIV, hepatitis, even "mad_cow" disease and isthrown out. Blood typing (A, B, AB, O) causes even more difficulties as to whether or not a person may receive the correct blood type. If you have the universal blood type O you may be out of luck, so to speak, when it comes to receiving other blood types. Or have you ever thought about animals that need surgery? Veterinarians do not usually stockpile different types of animals’ blood. Shortage of blood is a very real threat; by 2030, experts project an annual shortfall of 4 million units in the US. But, what if there were a way to prevent this shortage?
Pharmaceutical Corp. has developed a new blood substitute called
Oxygent, IUPAC name of perfluorooctyl bromide (see the structure using
ChemFinder), or Perflubron, which alleviates these problems. This substance
is an oxygen
carrier and can be used during surgeries safely
instead of blood. One
of oxygents many benefits is that a person of any blood type can receive
has been found, for example, that dogs treated with a 25% perfluorotributylamine-water
emulsion replacing 70% of their blood can still live a normal life span.
Oxygent can be used in various medical circumstances where blood is
needed for the transport of oxygen, with little or no known side effects
on the human body. Research similar to Alliance’s into patient response
and emission of the particles out of the body is currently still being
6.3. Common Uses of Alkyl Halides and following on to Structure and Physical
Chapter 6.6. Preparation of Alkyl Halides and following on to Nucleophilic Substitution.
Chapter 25.4. Relating to emulsions
1: Use ChemFinder to find out about the structures of the fluorocarbons
above, and draw the structure of the PFC with the IUPAC name of trans-perfluorodecalin.
Question 2: Is Oxygent a "blood substitute"?
A 2: Oxygent is a "blood
substitute" in the sense that it mimics the gas transport function
of the red blood cells, which contain a protein called hemoglobin that is responsible
for delivering oxygen and removing carbon dioxide from the tissues f the body.
There are no products on the market or in development that can substitute for all the
functions of blood provided by the red cells, platelets, white blood cells, and plasma
Question 3: What advantages does Oxygent have compared to donor blood?
A 3: UCan be used
in patients of any blood type.
UCan be heat_sterilized to prevent bacterial contamination; hemoglobin cannot.
UDoes not transmit viruses or other infectious agents.
UCan be stored for about two years, vs. about 42 days for donor blood.
UDelivers oxygen to tissues more quickly than the hemoglobin in red blood cells.
4: By what mechanism can 1-bromo-heptadecafluorooctane (perflubron) be prepared
Explain or illustrate)
4: Doing an Sn2 reaction of octadecafluorooctane
with a terminal fluorine as the
leaving group which is replaced by bromine in an aprotic solvent such as acetone or
Question 5: How do perfluorochemicals (PFCs) transport oxygen?
5: Oxygen molecules are dissolved in PFC particles
as they pass, in the blood, through
the lungs. These oxygen_loaded particles travel through the blood to distant
capillaries where tissue oxygen concentrations are low. At that point, oxygen is
exchanged for carbon dioxide molecules. PFCs exchange gases more rapidly and
more completely than do red blood cells because they load and unload gases by
simple diffusion. When the particles return to the lungs, the carbon dioxide is expired
and the PFC particles take on new oxygen molecules.
Chemistry & Society Discussion
Do you think it is ethical to make artificial blood substitutes?
Excellence is a habit!
Excelenta este un obicei!
L’excellence est une habitude!