A Clean One-pot Synthesis of Tetrahydrobenzo[b]pyran Derivatives Catalyzed by Hexadecyltrimethyl Ammonium Bromide in Aqueous Media - Jin, Tong-Shou; Wang, Ai-Qing; Wang, Xin; Zhang, Jian-She; Li, Tong-Shuang (Synlett, 2004)