Deprotonation of benzylic ethers using a hindered phosphazene base. A synthesis of benzofurans from ortho-substituted benzaldehydes.

The hindered nonionic phosphazene base P(4)-t-Bu efficiently deprotonates o-arylmethoxy benzaldehydes, leading to a direct synthesis of benzofurans. Strong ionic bases such as LDA, LiTMP, and KH failed.