The reaction shown above outlines the synthesis of the lupinine ester. These esters have been studied for their biological properties. Found mainly in plants there is heavy research being done on them for their antiviral, antitumor and hepatoprotective activity. In some cases lupinine esters can exhibit local anesthetic properties.

The reaction shows how you would synthesize a lupinine ester from betulonic acid chloride with lupinine. Side conditions for this reaction include the presence of triethylamine and must be performed in dry CCl4.

D,L-1,2,4-butanetriol can be made in two different ways; the first way is commercial synthesis through reduction of esterified D,L-malic acid with sodium borohydride, NaBH4, while the second way involves microbes. The latter method was the focus of the journal article. Nitration of racemic D,L-1,2,4-butanetriol results in D,L-1,2,4-butanetriol trinitrate, a compound that is the energetic equivalent of nitroglycerin, but is less shock sensitive, more thermally stable, and less volatile. One of the final steps in the synthesis of D, L-1,2,4-butanetriol via microbes is the reduction of a racemic mixture of D,L-3,4-dihydroxybutanal (aldehyde), to the final alcohol product, as seen in the reaction below. The catalyst for the reaction is dehydrogenase from E. coli.

The following paper presents an efficient and environmentally friendly method for producing phosphate monoesters, in which the only byproduct is water, as opposed to a different reaction, which also gives off pyridine hydrochloride as a byproduct.
The paper describes that it was experimentally determined that the best solvent, tertiary amine, and catalyst (or nucleophilic base) for the reaction are DMF-nitroethane, tributylamine, and N-butylimidazole, respectively, each giving the highest yield. This is a summary of the main reaction discussed in the paper.
* The article states that water was constantly removed by azeotropic reflux, so that the reverse reaction was prevented.

The sulfonium salt S-adenosylmethionine is one of the most widely used biological methylating agents. It is formed by the ATP activation of methionine. One of the most benifical uses of this salt is to convert norepinephrine to epinephrine (adrenaline). Many times this conversion happens in flight or fight organs, which leads to vasodilatation. This vasodilatation in turn leads to an increased blood flow to the organ/tissue or interest.

The reaction shown is the formation of S-Adenosylmethionine. This process occurs in two steps as can be seen. The first step cleaves the whole phosphate of the ATP. However before the sulfur of methionine attacks the C5` atom of ATP (via SN2) there is further hydrolysis of the cleaved tri-phosphate into two inorganic phosphates (di and mono).

This is a nitrate ester made by esterification. In this process, glycerols reacts with Nitric Acid under a catalyst of Sulphuric Acid at 300oC to yield an ester complex of glyceryl trinitrate otherwise known as nitroglycerine, and three water molecules. In this process, there has been formation of an ester bond (COO). This production is very crucial for medical purposes. Nitroglycerine is used to relieve angina, a condition when the heart isn’t receiving much oxygen. Also, Nitroglycerine was used in a study with yohimbine/l-arginine combination to see the treatment of erectile dysfunction in males. The metrics used in this study were the male’s systolic and diastolic blood pressures. This study created a correlation between the effects of erectile dysfunction with the inadvertent cause of coronary artery disease. Intravenous Nitroglycerine was used to help in the study with the chemical compositions with arginine.