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Let's go Sailing... The following is a sequential description that may be used when teaching the organic chemistry chart called Let's Go Sailing....The template of the mizzen mast sailboat is the key to making organic reactions simple, easier, and more fun for you and your students.
Begin by discussing organic reactions and reminding the students that over 90% of all compounds contain carbon. In number there are millions of molecules classified as organic molecules, and that number increases each year because of synthesis. Organic chemistry is the chemistry of only a few atoms: carbon, hydrogen, oxygen, sulfur, nitrogen, phosphorus and the halogens. These atoms covalently bond to produce molecules of different types. They combine to form different classes of organic molecules that differ in their functional groups. Knowing their position on the sailboat template is very important, and will aid you in their reaction, and their synthesis process. The simplest classes are the alkanes, alkenes, and the alkynes. These are known as hydrocarbons because they are made up of only carbon and hydrogen atoms. As a biochemist, I also lecture on one of the possible theories for the formation of life. This theory maintains that life could have started with only three simple molecules: methane CH4, ammonia NH3, and water H20, respectively, sources of carbon, nitrogen, and oxygen. All contain hydrogen atoms. In these three simple molecules, we have the atoms for building millions and millions of organic molecules. These include carbohydrates with the general formula of C(H20)n. Carbohydrates are one of the four main macromolecules (macro- meaning large) necessary for life. Amino acids are also made up of just four atoms carbon, hydrogen, oxygen and nitrogen atoms. Amino acids are the precursors of proteins, another one of the macromolecules needed to make living tissues. Lipids, another macromolecule, only contain C, H, and O, atoms. These are the primary components making up the morphology of all cells. With the addition of the phosphorus atom, nucleic acids, may have been created. Deoxyribonucleic acid, DNA, carries the genetic code and also determines the kind of proteins that will be synthesized in the cell. Ribonucleic acid, RNA, is found in three different forms: messenger m-RNA, transfer t-RNA, and ribosomal r-RNA. Under the direction of DNA, the RNA molecules carry out protein synthesis in cells. These are found in the nucleus and also in the cytoplasm of cells. Energy molecules, which are necessary for life, could be synthesized from the same four atoms, carbon, hydrogen, oxygen, and phosphorus. The energy molecules: AMP, ADP, and ATP; known as adenosine monophosphate, adenosine diphosphate and adenosine triphosphate, respectively, are also main components necessary for life. Remind your students that only 13 atoms make up about 99% of all life forms that we know of on our planet. There is a saying that will aid your students in remembering these 13 atoms. "See, HOPKINS, cafe more salt" which stands for the atoms: carbon, hydrogen, oxygen, phosphorus, potassium (Latin name: kalium therefore the symbol "K"), iodine, nitrogen, sulfur, calcium, iron; (Latin name: ferrium symbol, "Fe"), magnesium, sodium (Latin name is natrium, its symbol is "Na") and chlorine. These 13 atoms are abundant in the earth's crust. The Let's Go Sailing... chart also starts out with an inorganic compound, calcium carbonate, as the starting material; therefore pointing out the importance of inorganic chemistry before the study of organic chemistry in the synthesis of the very reactive organic molecules.
the tiller The tiller, therefore, is the driving force of the sailboat!!! In the illustration below we will start with the aft (back) mizzen mast.
Alkynes are carbon to carbon triple bonded. That means they share three pairs of electrons between one set of carbon to carbon atoms. Their generalized formula is CnH2n-2. Note it also contains two cracking reactions. Cracking is accomplished with the aid of a catalyst at temperatures of 400 to 600 degrees Celsius. Note the reactions from the alkanes to alkenes and alkynes making up the side of the main sail. Also note the cracking reaction on the bottom of the sail between the longer alkanes and the alkenes. The addition reaction on the bottom of the sail converts the unsaturated double bonded alkene to a saturated alkane. Saturated hydrocarbons contain the maximum number of hydrogen atoms per carbon atom. The catalysts that speed up this reaction are platinum (Pt), nickel (Ni), and / or palladium (Pd).
As mentioned above carboxylic acids are very reactive and are therefore, involved in many organic reactions. You will notice that the Carboxylic acid molecule is the point of origin of almost all of these reactions. The first reaction that I usually teach is the esterification reaction. This is also the point at which the students perform an Esterification Svnthesis lab. Esters are aromatic molecules that have a variety of odors and flavors. Esters are natural as well as artificial flavors. "Ester, Ester, I know her well, she tastes so fine, and her aroma is so swell". This should help your students remember the properties of esters. You may use any ester lab of your choice. Esters, like many organic molecules can be hydrolyzed and be converted into a different type of organic compound. Hydrolysis is the addition of water (HOH). Esters form carboxylic acids when hydrolyzed. Acyl halides may also be hydrolyzed to carboxylic acids. Acyl halides contain the carbon to oxygen double bonded carbonyl group, along with a halogen atom. They may be synthesize from carboxylic acids, by a substitution reaction with phosphorus trihalide (PX3). Acyl halides will produce amide molecules by a substitution reaction with ammonia (NH3). Note that this reaction is not reversible. Amides have an amino, -NH2, group where acyl halides have a halogen atom. Amides will hydrolyze to carboxylic acids, and carboxylic acids will form amides by a substitution reaction with ammonia. Therefore, we see there are numerous reactions centered around carboxylic acids. One last reaction on this page is the conversion of the acyl halide to an ester by the addition of an alcohol, in this case the alcohol used is ethanol. Ethanol is grain alcohol which is very common in organic reactions. One of the abbreviations used for ethanol is Et-OH.
The Methane "Sailboat" We will now turn our attention to a specific example using the Let's Go Sailing.... chart as our guide and breaking it down again. Starting with methane (CH4), at the top of the back mast we will go through all the reactions.
Methane reacts with chlorine gas in the presence of ultra violet light to replace one of the hydrogen atoms with a chlorine atom forming methyl chloride. Methyl chloride, an alkyl halide, reacts with sodium metal to produce ethane. We have now "doubled" the size of the carbon chain. This longer alkane is halogenated by a substitution reaction with bromine (Br2). Ethyl bromide undergoes a dehydrohalogenation reaction, eliminating a hydrogen atom and a bromine atom to form ethene. As noted on the chart, this is accomplished by the strong base potassium hydroxide in an alcoholic solution. The alkene, ethene will add two bromine atoms to the double bond to produce 1,2-dibromoethane. One bromine atom was added to each of the carbons atoms. The diatomic bromine molecule was dissolved in the carbon tetrachloride solvent to achieve the above addition reaction. If another elimination reaction is performed by potassium hydroxide with sodium amine, acetylene gas is produced. Ethyne is the name of choice for this molecule because it denotes that this is a carbon to carbon triple bonded molecule. Historically, welders have used acetylene for ages, but this is a misnomer because having the suffix -ene, confuses students. however, it was known under the common name of acetylene. Ethyne will react with two moles of hydrobromic acid to break the carbon to carbon triple bond to form 1,2- dibromoethane. When the dihalogenated alkane reacts with zinc metal, the bromine atoms will be eliminated to produce ethene. Again the "pi" (π) bonds of the carbon to carbon double bond will break to form ethyl bromide. Also note that by a cracking reaction alkanes will be broken down to form alkenes and alkynes. The addition of hydrogen gas (H2), to ethene with the catalysts of platinum, palladium, and / or nickel, will make the unsaturated ethene become saturated forming ethane. A substitution reaction will transform ethyl bromide into the first degree alcohol, ethanol.
Ethanol is a primary alcohol that also goes by the common name ethyl alcohol. Ethanol can become ethyl bromide by another substitution reaction with phosphorus tribromide. To change a primary alcohol into an aldehyde we may used copper(II)oxide to oxidize ethanol into ethanal. This reaction requires a temperature of 250 degrees Celsius. The aldehyde can add on additional carbon atoms using a Grignard reageant such as methyl magnesium chloride to form propanol, which has the formula CH3CH2CH2-OH. Notice that propanol is three carbon atoms long. This is not depicted on the chart but is important in the synthesis process.
Finally, we will form the ester, ethyl acetate, by reacting acetic acid with concentrated sulfuric acid in ethanol. Ethyl acetate may also be formed from acetyl chloride by reacting it with ethanol. Ethyl acetate can be hydrolyzed to acetic acid which in turn can go back to ethyl acetate by a substitution reaction with phosphorus trichloride. Acetic acid will also undergo these same two reactions, substitution, and hydrolysis with acetamide. This concludes this example, although many more are possible. Have your students make up some more examples. As one of the teachers that I presented to at National Science Teachers Association (NSTA) convention in Alantic Georgia said: "The organic chemistry chart entitled Let's Go Sailing... is to organic chemistry what the periodic table is to inorganic chemistry." That may be true for high school students but definitely NOT for college students as most of the reactions are highly generalized. This is by no means the real thing, but it is neat. Enjoy.
Good
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that is a carbon to oxygen double
bonded group. This same functional group will be found in three other
types
organic molecules. Aldehydes can also be oxidized to carboxylic acids.
To accomplish this potassium permanganate (KMnO4), will be used.
Carboxylic acids are another hub of organic reactions. Carboxylic acids can be
oxidized to ketones by using MnO2, manganese(IV)oxide.
Carboxylic acids are weak acids and, like inorganic acids, can react with a
base to produce an organic salt. Acids + Bases ----- > Organic Salts +
water. This, like in the study of inorganic chemistry, is called a
The "generic sailboat" outline, shows the general
names and reactions that deal with the keel (bottom) portion of the sailboat.
Alkenes, C=C, will under go an addition reaction with diluted, (6.0 M) sulfuric
acid (H2SO4). To produce an alkyl hydrogen sulfate.
This reaction is reversible if you heat the alkyl hydrogen sulfate at 180
degrees Celsius. This is known as an elimination reaction. Alkyl hydrogen
sulfates may also be converted into another class of organic compounds known as
ethers. Note that this reaction is not reversible. Ethers have the
general formula of R--O--R, where R may be an alkyl group, or aryl group, but
not a hydrogen atom. Ethers where first used as general anesthetic for
surgery. The most widely known diethyl ether. Also note that this reactions is
termed a substitution reaction. The conditions for this type of reaction are a
temperature of 140 degrees Celsius and the addition of ethanol. Alkyl hydrogen
sulfates can be converted to alcohols by hydrolysis. Alcohols may be changed
into alkyl hydrogen sulfates by a 
