Synthesis of Cyclotriveratrylene (CTV) Derivatives

Cyclotriveratrylene (CTV, 1) was the starting material for the synthesis of various CTV derivatives. The derivatives of CTV synthesized were its monoketone 2, diketone 17, spirolactone 16, oxime conformers 3 and 4, lactam 5, N-acetyl amide 12, and anthracenes 29 and 30. The oxidized products of CTV, monoketone 2 and diketone 17 were synthesized utilizing slightly basic conditions that increased the rate of reaction, made isolation of the desired oxidized products easier, and eliminated the formation of spirolactone 16. The oxime of CTV has been prepared and the individual crown (3) and saddle (4) conformers were isolated and characterized. The equilibrium constant was measured in CDCl3 and in DMSO-d6 and was shown to favor the crown conformer by an order of magnitude in DMSO-d6, relative to an approximately equal mixture at equilibrium in CDCl3. The time course for interconversion of the saddle to the crown was measured by 1H NMR and the t1/2 of the saddle was determined to be 2.45 hours in CDCl3 at 25 oC, and 3.71 hours in DMSO-d6. 3 The Beckmann rearrangement has been performed on the oxime of cyclotriveratrylene (CTV) (3) with thionyl chloride affording the ring-expanded 10-membered lactam (5) exclusively in high yield. Modified conditions afford a helical pentacycle (6) derived from an unusual tandem Beckmann rearrangement and electrophilic aromatic addition followed by demethylation and tautomerization. The crown shaped 10-membered N-acetyl macrocyclic amide 12 crystallized as a solid solution of racemic columnar assemblies comprised of alternating enantiomers in a stacked cup array, each as a chloroform solvate but with a random distribution of the columnar assemblies within the crystal leading to whole molecular disorder within the crystal. The rearranged anthracenes 29 and 30 formed through bromination of CTV diketone 17 are of interest due to their potential chemiluminescent/electroluminescent properties and thus could be utilized for OLED’s (organic light emitting diodes) or molecular switches/motors