10.1039/jr9560002609
The research explores the synthesis of complex aromatic compounds through the self-condensation of specific benzothionaphthen dioxides. The primary purpose is to develop new routes for the synthesis of 1-1'- and 4-2'-naphthylphenanthrene, which are significant for their potential applications in the field of organic chemistry and materials science. In the research, sodium sulphite (Na?SO?) plays a crucial role as a reducing agent. It is used in the synthesis of 2-1'-naphthylethanesulphonyl chloride (VII) from 2-1'-naphthylethanol (VI). Specifically, sodium sulphite is employed to convert the bromide intermediate into the sulphonyl chloride, which is a key precursor for the subsequent cyclization and dehydrogenation steps leading to the desired sulphones. This transformation is essential for the overall synthesis of the complex aromatic compounds, such as 4:5-benzothionaphthen 1:1-dioxide and 6:7-benzothionaphthen 1:1-dioxide, which are central to the study. The research concludes that the developed synthetic routes are effective, albeit with some challenges in yields and separation of by-products. The findings highlight the utility of these methods for synthesizing large aromatic molecules, which could be valuable for future research in organic synthesis and the development of new materials.
10.1021/ol900118d
Lawrence L. W. Cheung and Andrei K. Yudin from the University of Toronto presents a novel method for synthesizing aminocyclobutanes from ?-lactams. The study explores the ring expansion of N-vinyl-?-lactams to form eight-membered enamide rings via a [3,3] sigmatropic rearrangement, and further conversion to fused cyclobutane d-lactams through electrocyclization. The ?-lactam starting materials are prepared through a multi-step process involving cycloaddition, reduction, and cross-coupling reactions. Sodium sulfite is used to reduce the N-chlorosulfonyl ?-lactam to the corresponding N-H ?-lactam. This reduction step is critical for preparing the ?-lactam intermediate for further reactions. The study demonstrates high diastereoselectivity in the formation of fused cyclobutane d-lactams, with the reaction yielding best results when using N-vinyl-?-lactam as the starting material without isolating the intermediate [3,3] sigmatropic rearrangement product.
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