翻译 We believe that another driver for investigating spirocycles is to access novel compounds in untrammeled patent space where broad generic scope can successfully be claimed. Monocyclic ring systems have been extensively investigated; however, as has been pointed out for fused ring systems in general, combination of two (or more) monocyclic ring systems provides a multiplicity of spirocycles, many of which have not been synthesized let alone tested for biological activity. A body of work from the Carreira group describing the synthesis of spirocycles incorporating four-membered rings illustrates this point。Given the growing literature describing the synthesis of spirocycles, their increased availability from building block vendors, and the desire to move away from highly (hetero)aromatic structures, it seems certain that spirocycles will enjoy even greater use in medicinal chemistry in future.
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