Multi-gram syntheses of four crown ethers using K+ as templating agent. Issue 3 (21st January 2016) - Wessels, Hanlie R.
Abstract: Dibenzo-30-crown-10 (DB30C10, 1c ), dibenzo-24-crown-8 (DB24C8, 1a ), 4-carbomethoxydibenzo-24crown-8 (1b ) and a new crown ether, 4-carbomethoxydibenzo-30-crown-10 (1d ), were synthesized by a simple, high yielding, three-step method. Potassium ions from the highly soluble KPF6 were employed to template the cyclization step, which resulted in very high isolated yields (80–90%). Graphical abstract: