Liu, Ren-Ming; Zhang, Min; Han, Xiao-Xue; Liu, Xiong-Li; Pan, Bo-Wen; Tian, You-Ping; Peng, Li-Jun; Yuan, Wei-Cheng published an article in 2022, the title of the article was Catalytic asymmetric Michael/cyclization reaction of 3-isothiocyanato thiobutyrolactone: an approach to the construction of a library of bispiro[pyrazolone-thiobutyrolactone] skeletons.Formula: C4H8ClNOS And the article contains the following content:
The first example of 3-isothiocyanato thiobutyrolactone serving as a useful building block in the Michael/cyclization reaction with alkylidene pyrazolones for the enantioselective construction of optically active structural bispiro[pyrazolone-thiobutyrolactone] skeletons containing three contiguous stereocenters with two spiroquaternary stereocenters was demonstrated. These products were smoothly afforded in up to 90% yield, >20 : 1 dr and >99% ee with chiral squaramide as the catalyst under mild conditions. Notably, this is also the first example of the merger of a spirocyclic pyrazolone scaffold with a spirocyclic thiobutyrolactone scaffold, potentially useful in medicinal chem. The experimental process involved the reaction of 3-Aminodihydrothiophen-2(3H)-one hydrochloride(cas: 6038-19-3).Formula: C4H8ClNOS
The Article related to isothiocyanato thiobutyrolactone alkylidene pyrazolone squaramide tandem michael spirocyclization reaction, bispiro pyrazolone thiobutyrolactone preparation diastereoselective enantioselective and other aspects.Formula: C4H8ClNOS
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