Two directional approach to spirocyclic ethers <i>via</i> Grignard reaction and ring-closing metathesis

1099-1106Diverse and intricate bis-spirocycles have been assembled via a Grignard reaction and ring-closing metathesis (RCM) as key steps. Readily available starting materials have been used and mild reaction conditions employed to generate a variety of intricate spirocyclic ethers containing pyran ring system. The scope of this methodology has then been expanded by synthesizing a spiro-dihydrofuran derivative