A novel, potentially prebiotic synthesis of RNA is proposed in which t
he key steps are an aldol mode of polymerisation, intramolecular redox
transfer and ring closure via a mesomeric heterocyclic betaine interm
ediate. The key monomers tn this scheme are derivable, in theory, from
the presumed prebiotic compound, bis(glycoaldehyde) phosphodiester 1
via its mono-formaldehyde aldol adduct 2.