15. Benzene and Aromaticity • C-Phen DM Drops (Chlorpheniramine/Dextromethorp/Phenylephrine) • This combination medication is used to treat symptoms caused by the common cold‚ flu‚ allergies‚ hay fever‚ or other breathing illnesses (e.g.‚ sinusitis‚bronchitis). • One of the active ingredients is Phenylephrine –a decongestant that helps relieve stuffy nose symptoms. H HO OH H N CH3 . HCl What is the configuration at this chirality center? R or S ? www.primaryrx.com/pdf/C-PHEN%20DM%20DROPS
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Rules for aromaticity 1. A cyclic planer structure and each atom must have a P orbital so that the electron cloud is not intterupted 2. It must contain an odd number of electron pairs ▪ i.e. the number of electrons must be 4n+2 where n=0‚1‚2‚3‚4……… ▪ so the number of electrons is 2‚6‚10‚14‚18……. ▪ this rule is called the Hückel’s Rule • monocyclic hydrocarbons with alternating single and double bonds are called annulenes • annulenes are named as [n]-annulene
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Analysis of Hydrocarbons Jessa Grace B. Castillo* and Stephanie Chua Department of Chemistry‚ University of Santo Tomas‚ Manila‚ Philippines ______________________________________________ Hydrocarbons are organic compounds containing only hydrogen and carbons and further divided in major types. Hydrocarbons react differently in reagents. The basis of determining an unknown hydrocarbon is due to the differences in reactions of hydrocarbons. An unknown compound is determined using tests.
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electrons from the aromatic ring serve for the ring to act as a nucleophile and attack an electrophile. For nitration‚ this nucleophile is NO2+‚ which is produced by reacting nitric and sulfuric acids. After the nucleophile adds‚ the ring has lost aromaticity. Therefore‚ the deprotonated acid in solution can pull off a hydrogen from the same carbon that the nitro group has added to‚ allowing the electrons from that bond to go back into the ring to reproduce aromaticty. There are three possible positions
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Vegetative reproduction (vegetative propagation‚ vegetative multiplication‚ vegetative cloning) is a form of asexual reproduction in plants. It is a process by which new individuals arise without production of seeds or spores. It can occur naturally or be induced by horticulturists. Although most plants normally reproduce sexually‚ many have the ability for vegetative propagation‚ or can be vegetatively propagated if small pieces are subjected to chemical (hormonal) treatments. This is because meristematic
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CH 16 - the name of this functional group class is historically derived from the pleasant aromas associated with many of its constituent compounds discovered in past centuries - although not all aromatic compounds known today share the same distinction (many are in fact‚ odorless or even unpleasant)‚ they are the principle components in such pleasant smelling substances as cinnamon‚ licorice‚ wintergreen‚ clove & vanilla CLASSIFICATION – - also known as arenes‚ many aromatic compounds possess
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substitution involves an initial rate determining interaction of the π system with the electrophile to give a benzenonium ion intermediate (σcomplex or wheland complex)‚ which undergoes a rapid de-protonation by the base in the second step to restore aromaticity (Figure 3). E H E H + E+ E H fast E + HB+ B Figure 3. Some common electrophilic aromatic substitution reactions are: halogenation‚ nitration‚ sulfonation‚ Friedel-Crafts Acylation and Friedel-Crafts alkylation. These differ
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explain its high stability was not suggested until 1866 by German chemist August Kekulé.1 His theory suggested that benzene was a hexagonal molecule containing three‚ alternating double bonds. This theory gave insight that lead to the field of aromaticity. After examining benzene’s heat of hydrogenation‚ Kekulé’s model was still not sufficient in explaining benzene’s stability. His theory was eventually replaced by resonance theory‚ which asserts that benzene does not have three alternating double
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Experiment H: Identification of an Unknown Organic Compound The objective of this lab was straightforward. We were given an unknown compound and we were to perform an IR spectroscopy and as well as NMR spectroscopy. With the IR spectroscopy‚ I was able to name the functional groups I have on my compound and further confirmed my assumptions by looking at the NMR spectroscopy after. The unknown number I was given was number 203. The molecular weight of the compound was 121. From the molecular weight
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Chemistry S-20 Week 1 Alkenes: Isomers and Nomenclature 1. There are 6 unique alkene isomers of the hydrocarbon C5H10. Draw each of these isomers‚ and provide a systematic name for each. 1-pentene (E)-2-pentene (Z)-2-pentene 2-methyl-1-butene 2-methyl-2-butene 3-methyl-1-butene 2. For the three alkenes above which are various isomers of pentene‚ rank them in order of stability. Explain your ranking. most stable (more subst. double bond) less stable (cis alkene is
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