Synthesis and conformations of a water-soluble cyclic tetramer obtained from reacting 5-sulfonatotropolone with formaldehyde

Article abstract of DOI:10.1016/S0040-4020(97)00534-6

A water-soluble cyclic tetramer 3 has been synthesized from reacting 5-sulfonatotropolone with formaldehyde. In D₂O at 25°C it existed in three major conformations (cone, 1,2-alternate and 1,3-alternate) with a trace amount of partial cone conformation. The latter increased with temperature. All the four conformers were observed in DMSO-d₆ at 25°C.