10.1055/s-2007-1000858
The research study on the synthesis and alkylation of phenols with α-(n-alkylcarbonyloxy)alkyl (ACOA) halides, focusing on the impact of steric hindrance on the reaction path. The experiments involved the synthesis of ACOA iodides and their subsequent reaction with 4-hydroxyacetanilide (acetaminophen, APAP) and 2,2,5,7,8-pentamethyl-6-chromanol, a sterically hindered phenol. The aim was to determine if steric hindrance affected the ratio of acylated to alkylated products. Various reaction conditions were tested to maximize the yield of the desired alkylated product. The reactants included different ACOA halides with varying alkyl chain lengths and phenols with different steric hindrance. The analyses used to determine the product distribution included 1H NMR spectroscopy and melting point determination, with purification methods involving column chromatography and crystallization. The study found that steric hindrance was not a significant factor in the reaction outcomes, suggesting that n-alkyl ACOM and ACOA promoieties could be viable alternatives to pivalate-based derivatives, which are associated with toxicity.
10.1002/chem.201603722
The study primarily investigates the behavior of hydroperoxyl (HOOC) and alkylperoxyl (ROOC) radicals in hydrogen atom transfer (HAT) reactions, with a focus on their interaction with 2,2,5,7,8-pentamethyl-6-chromanol (TOH), an analogue of vitamin E. The researchers used 1,4-cyclohexadiene (CHD) and styrene as substrates to monitor the autoxidation rate in various organic solvents, which served as a means to assess the reactivity of HOOC and ROOC with TOH. The purpose of these chemicals was to understand how HOOC radicals, which are implicated in oxidative damage in biological systems, behave differently from ROOC radicals during H-atom transfer and how they affect the regeneration of TOH, providing insights into the antioxidant properties of vitamin E and the role of solvent effects on these reactions.
10.1246/bcsj.82.829
The study explores a novel synthetic route to produce (All-rac)-α-tocopherol acetate, a form of vitamin E, using linalool and dihydromyrcene as starting materials. The researchers employed trimethylhydroquinone (2) as a key reactant and utilized camphorsulfonic acid as a catalyst to condense it with linalool (3b) in a solvent mixture of dodecane and dichloromethane. The resulting crude product, a mixture of chromanols and tricyclic compounds, was sequentially treated with acetic anhydride (Ac2O) and m-chloroperoxybenzoic acid (m-CPBA) to form a mixture of epoxides. This mixture was then converted to the desired (All-rac)-α-tocopherol acetate through a series of reactions involving aluminum isopropoxide, copper(I) iodide-catalyzed Wurtz coupling with citronellylmagnesium chloride, and hydrogenation. The study aimed to develop a more efficient and cost-effective method for synthesizing this important vitamin E derivative, which is widely used in the feed industry due to its antioxidant properties and health benefits.
