10.1055/s-2007-990834
The research focuses on the development of a simple and efficient method for synthesizing new mono- and bis([1,2,4]-oxadiazol)benzaldehyde building blocks, which are valuable in organic chemistry for a variety of applications. The purpose of this study was to create a high-yielding, five-step procedure with minimal and straightforward purifications, starting from readily available benzamidoxime, derived from 4-cyanobenzaldehyde. The conclusion of the research is that the team successfully developed a general method for synthesizing these compounds with aromatic and aliphatic linkers, yielding overall yields between 66% and 80%. Key chemicals used in the process include 4-cyanobenzaldehyde, ethylene glycol, p-toluenesulfonic acid, hydroxylamine hydrochloride, sodium carbonate, pyridine, phenylacetyl chloride, and various dicarboxylic acids or acid dichlorides to introduce different linkers. The final products, the mono- and bis([1,2,4]-oxadiazol)benzaldehydes, were obtained through a series of reactions involving O-acylation, acetal deprotection, and cyclization steps.
10.1016/S0040-4039(00)87517-6
The research focuses on the synthesis of novel 1,3-diazabicyclo[3.2.0]heptane-2-carboxylic acid derivatives, aiming to enhance the antibacterial activity of these compounds by incorporating a carboxylic acid side chain. The study involves the preparation of two key derivatives: 4-methoxycarbonylmethyl-7-oxo-1,3-diazabicyclo[3.2.0]heptane-2-carboxylic acid and 7-oxo-6-phenoxycarbonylamino-1,3-diazabicyclo[3.2.0]heptane-2-carboxylic acid. The process utilizes a series of chemical reactions, including the addition of mixed anhydrides, reduction with hydrogen sulfide, acylation with phenylacetyl chloride, and ozonolysis.
10.1021/jo01323a029
The study investigates the acylation-cycloalkylation reaction of phenylacetyl chloride with cyclohexene, focusing on the formation of cyclic ketones. The aluminum chloride complex of phenylacetyl chloride reacts with cyclohexene to produce cis-hexahydro-9-phenanthrone (3) along with other products like chloro and unsaturated ketones. The reaction's stereoselectivity and the stability of the products under various conditions are explored. The study also examines the reaction with 1-methylcyclohexene, yielding cis- and trans-methylhydrophenanthrones (30 and 31). The stereochemistry of the ketones is established through conversions to known compounds. The stability of cis-hydrophenanthrone (3) is notable, as it resists isomerization under Friedel-Crafts reaction conditions but readily converts to the trans isomer (2) in the presence of acid, base, or heat. The study provides insights into the reaction mechanism and the factors influencing the selectivity and stability of the products.
C
