An Efficient and Direct Solvent-Free Synthesis of Naphtho[1,2-b]furans, Naphtho[2,1-b]furans, and Furo[3,2-c]chromenes - Adib, Mehdi; Mahdavi, Mohammad; Bagherzadeh, Sharareh; Bijanzadeh, Hamid Reza (Synlett, 2009)