Direct anti and regio-specific aldol reactions of cyclododecanone catalyzed by alkali metal hydroxides: implications for supramolecular helical design

Towards A New Approach for the Description of Cyclo–2,4-Dihydroxybenzoate, A Substance Which Effectively Mimics Zearalenone in Imprinted Polymers Designed for Analyzing Selected Mycotoxins in Urine

“…However, a careful analysis reveals the sequence of torsion angles identical in both molecules that can be described as p–2s-p–2s-p-5s, where p and s denote anti-periplanar and synclinal torsion angles. In contrast, a typical conformation of cyclo-dodecyl moiety as found in the CSD database (Cambridge Structural Database) [35], is described by the sequence of torsion angles p–2s-p–2s-p–2s-p–2s e.g., in [36,37]. In the reported CDHB structure, however, the superposition reveals that the same conformation of cyclo-dodecyl moiety in two molecules can be obtained with such rotation of the rings that C8 and C9 positions in Molecule 1 coincide with Molecule 2 C28 and C39, respectively.…”

A mild and efficient one-pot three-component synthesis of anti-β-amino-carbonyl compounds catalyzed by NH4OAc and their anticancer activities

“…This unique reaction was produced only by CDD and not by any other cyclic ketone. In the formation of anti-aldol product (Sathesh et al, 2012) and aldol product involving pinacol coupling reaction (Tsuritani et al, 2000) CDD gives only anti-diastereoselective products. This was possible by ammonium acetate because of its dual nature.…”

“…Aniline -NH group is in pyramidal configurations. The CDD ring adopts [3333] square conformation (422 symmetry) in all the three compounds (Sathesh et al, 2012;Anet, 1974;Dale, 1976). The numbers in the square brackets indicate the number of ring bonds between the four corner atoms of the CDD ring.…”

“…The conformation of CDD is different from other cyclic (cyclohexanone) and acyclic ketones, since it (CDD) suffers from ring strain and bad transannular interaction (Sathesh et al, 2012;Goodman et al, 1995;Rawdah, 1991), which are observed in higher cyclic ketones (n [ 7) (Rawdah, 1990;Ledaal, 1968) as shown in Fig. 1.…”

“…Ketone is supposed to play a major role in diastereoselectivity. The CDD takes part in the reaction in the form of a W-shaped zwitter ion with dynamic equilibrium in [3333]-2-one square conformation (Sathesh et al, 2012;Goodman et al, 1995).…”