31. Once the heptapeptide backbone has been formed, the cyclization of the linear structure is begun. 32. Short Synthesis of Skeletally and Stereochemically Diverse Small Molecules by Coupling Petasis Condensation Reactions to Cyclization Reactions 33. This forms the reactive intermediate number 2 species, the 3-exo-trig cyclization . 34. The iminium specis created by cyclization is then reduced to the tertiary amine, yielding agroclavine. 35. Cycloheptanone is still produced by the cyclization and decarboxylation of suberic acid or suberic acid esters. 36. The conditions under which these cyclization reactions occur follow Baldwin's rules for ring closure. 37. Its binding pocket also properly orients the iminium intermediate during cyclization to disastereoselectively produce its alkaloid products. 38. In this process, benzaldehyde and methyl isocyanoacetate undergo cyclization in the presence of a aldol reaction. 39. This allows for the Bergman cyclization to occur at 37 �C, the biological temperature of humans. 40. Butelase 1 is the fastest peptide ligase known capable of catalyzing peptide cyclization at an extraordinary efficiency.
