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You are using Science Of Synthesis as a Guest. Please login or sign up for a free trial to access the full content. Method 1: By the Simonis Reaction

DOI: 10.1055/sos-SD-014-01084

Murphy, P. J.Science of Synthesis, (200314863.

It has been reported[‌19‌‌22‌] that reaction of benzeneselenols with either β-oxo esters or malonic acid derivatives in the presence of a strong acid (a Simonis-type reaction) leads to 1-benzoselenopyran-4-ones and/or 1-benzoselenopyran-2-ones. For example, reaction of the substituted benzeneselenols 30 with β-oxo esters 31 or diketene 32 leads to the 4H-1-benzoselenopyran-4-ones 33; however, the yields are always low (Scheme 11).[‌19‌,‌20‌] Similarly, reaction of the benzeneselenols 34 with malonic acids 35 leads to the 4-hydroxy-2H-1-benzoselenopyran-2-ones 36; again, the yields for this process are poor.[‌21‌] A slightly different reaction occurs when the malonic esters 37 are utilized in this reaction, in that the 2-(phenylselanyl)-4H-1-benzoselenopyran-4-ones 38 are obtained in 2030% yield (Scheme 11).[‌22‌]

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