Aromatization-driven cascade [1,5]-hydride transfer/cyclization for synthesis of spirochromanes†

An aromatization-driven hydride transfer-involved α-C(sp³)–H bond functionalization of the oxygen atom was developed. In this transformation, easily prepared p-quinone methides were applied as aromatic precursors to initiate a [1,5]-hydride transfer/cyclization reaction for generating cyclohexadienone fused spirochromanes. A variety of spirochromanes, including privileged molecules with two spirochromane moieties linked by an alkenyl or a phenyl group, were obtained in high efficiency. In addition, the derivatizations of products were conducted to further enrich the diversity of the structure.