Dipolar Cycloaddition of Dicyclopentadiene with 3-Oxidopyrylium Betaine: An Entry into Methano-Bridged 5-6-7-Fused Ring System - Yadav, Arun A; Sarang, Prajakta S; Wannere, Chaitanya S; Trivedi, Girish K; Salunkhe, Manikarao M (Synthesis, 2008)