Hydrazino-Spengler Essay

The reaction involves a nucleophilic acyl substitution on an aldehyde, with the leaving group concurrently attacking another aldehyde in the second step. First the Potassium hydroxide attacks a carbonyl, which forms a tetahedral intermediate which then collapses when attacked by another hydroxide. The carbonyl is formed again when its hydride attacks another carbonyl. In the final step of the reaction, the acid and alkoxide ions formed exchange a proton. In the presence of a very high concentration of base, the aldehyde first forms a doubly charged anion from which a hydride ion is transferred to the second molecule of aldehyde to form carboxylate and alkoxide ions. Subsequently, the alkoxide ion acquires a proton from the solvent.

The SN1 mechanism leads to substitution products, and the E1 mechanism leads to formation of alkenes, therefore in this case, it is shown that this mechanism leads to a substitution of products since the Cl- ion is replacing the OH group by the addition of a strong acid (HCl). When the nucleophile

1. Purpose: to clarify the mechanism for the cycloaddition reaction between benzonitrile oxide and an alkene, and to test the regiochemistry of the reaction between benzonitrile oxide and styrene.

In this reaction, a rate-determining step should occur through the ionization between carbon and –OH bond to form an intermediate.11 This step should be followed by rapid reaction of a nucleophile to wrap up the substitution.11 For this experiment, hydrochloric acid was used to drive off the reaction, which contains a chlorine ion, a common nucleophile. (1)Chlorine ion is more effective as a nucleophile than water; because an ion holds a negative charge and resulting in a faster rate of reaction, whereas water holds a neutral charge, resulting in a slower rate of reaction with a carbocation intermediate.13 The starting

The reaction took place in a conical vial and .2mL of each of the reactant samples were added to it along with some 95% ethanol. Two drops of NaOH were added shortly after and stirred at room temperature for fifteen minutes. The vial was cooled in and ice bath and crystallized. Vacuum filtration was performed to filter the crude product. The crude product was recrystallized using methanol and filtered again. We made one change to the procedure and instead of using .7mL of ethanol we

Objective: The objective of this lab is to observe the synthesis of 1-bromobutane in an SN2 reaction, to see how a primary alky halide reacts with an alcohol.

The first step of the mechanism was to break the alkene pi bond and form a new C-Br bond. When the alkene broke, a secondary carbocation formed. The bromide anion attached to

Throughout the field of organic chemistry, one comes into contact with a multitude of reactions involving concerted mechanisms. An example which can be found in the Diels-Alder reaction, which occurs prolifically within organic reactions.3 Diels-Alder reactions fall under the category of 1,4-cycloaddition reactions and pericyclic reactions. Pericyclic reactions are concerted reactions that occur in a one-step process with a cyclic transition state in which bonding electrons are altered via a cyclic arrangement that allows bond to break and form synchronously. They are also dependent on the interaction between the symmetry of molecular orbitals.1,2 However, a Diels-Alder reaction is specifically known to be a [4+2] cycloaddition which occurs under heated conditions when a diene, which is a conjugated compound containing a pi system of 4π electrons, interacts with a dienophile, a compound known to contain a double bond consisting of 2π -electron system.1,2,3 Once the diene and dienophile have interacted, the resulting product is known as an adduct.2

The major product of this reaction is endo version of cis-Norbornene-5, 6-endo-dicarboxylic anhydride. The technique in this lab are applied by companies of the pharmaceutical industries. The use of Diels-Alders to construct rings for compositions of different drugs and medicines.

No other company has the long and storied history that Zildjian has. Approaching 400 years of age, Zildjian’s unparalleled legacy is as long and legendary its mysterious secret formula. As the story goes, Zildjian was founded by Avedis I in Constantinople all the way back in 1623. Zildjian cymbals quickly found use by composers in 1680 and by the 19th century, they had achieved a permanent spot in orchestras and were popularized by composers such as Wagner and Berlioz. Although Zildjian had a long and storied history in Europe, Zildjian’s history in America didn’t start until 1929 with Avedis III. Avedis III is credited for being the first to develop cymbals for drum-sets and established naming conventions for them including: ride, crash, splash,

The recent elucidation of the biosynthetic pathway for stipitatic acid led to the identication of a new FMO (TropB).4 This enzyme catalyses the oxidative dearomatisation of 3-methylorcinaldehyde 1 to produce a dienone 2 (Scheme 1A). This hydroxylation step is remarkably similar to one of the steps reported for the chemical synthesis of azaphilones and their analogues (Scheme 1B).5,6 The synthetic step requires extreme cold temperatures (
70 to
10 C), hazardous reagents and relatively long reaction time (30 h). It would be advantageous if related transformations could be performed bio-catalytically using TropB or a related enzyme. This would obviate the utilisation of dangerous chemicals and challenging reaction conditions to facilitate the

Cultural imperialism, in a form of New York’s World Expo in 1964, stands on the background of this part of the story. A young Javanese dancer, Sardono W. Kusumo was a member of the Indonesian dancer contingent for the expo. Extending his stay in the city that had become an adopted home or, depending on your viewpoint, a thrift store of world culture, there he met another young Indonesian, just a couple years his senior, an emerging poet cum theatre artist by the name of Rendra. The following six-months of his informal residency would be brief and memorable for Sardono and its significance to Indonesian performance field would continue to resonate until a few decades later.

This reaction occurs by reacting acetanilide with a HNO3/H2SO4 solution under cold conditions. During this reaction, the amide group attached to the number 1 carbon of aniline is a strong activating group that will direct the nitro group to bond in the ortho or para positions on the benzene ring, which occurs because of ortho-para directing of activating groups2. Initially, to start this reaction, 6.5 grams of solid acetanilide must be placed into 10 mL of glacial acetic acid and fully dissolved over a steam bath then cooled via ice bath with 10 mL of concentrated sulfuric acid. After the mixture had cooled, a cold HNO3/H2SO4 solution was added slowly to ensure that the reaction would not occur to quickly, which would hinder the reaction process. The yellow precipitate of nitroacetanilide was formed when 100 mL of cold water was poured into the mixture and filtered through a Buchner funnel..

The reaction began with the insertion of magnesium into the carbon-bromine bond to generate the Grignard reagent. 96 mg of magnesium turnings were ground up with a mortar and pestle in order to remove any surface oxides and contaminations that may preclude magnesium’s ability to react with unreactive alkyl halides. The magnesium turnings, along with a small crystal of iodine and a drop of 1,2-dibromoethane were added to a round bottom flask. The 1,2-dibromoethane is necessary to activate the alkyl halide. In a conical vial 2mL of anhydrous ether

The most prevalent problem in this case is whether Zespri is doing what is necessary to maintain its leadership position to increase New Zealand kiwifruit exports to $3 billion by 2025. In order to accomplish this, an additional problem they need to address is that they have to triple their global sourcing needs to satisfy demand when New Zealand fruit is out of the market. Zespri also needs to expand to more producers to develop vast amounts of kiwifruit during the off-season so that they are able to obtain their $3 billion dollar export goal.