400 mr ddr2

Chemicals used for the synthesis were obtained from commercial sources (Sigma Aldrich, St. Louis, MO, USA and Acros Organics, Geel, Belgium). Hexane, DCM, and EtOAc were acquired from commercial sources and were used after distillation. Molecular sieves were used to dry solvents denoted as dry. Other commercial reagents and solvents were used without further purification. The reactions were monitored with the aid of thin-layer chromatography (TLC Silica gel 60 F254) and pre-coated reverse-phase gel plates (TLC RP-18 F254). All operations involving air-sensitive reagents were performed under an inert atmosphere of dry argon and dried solvents. Melting points were determined using a melting point apparatus (PGH Rundfunk-Fernsehen, Niederdorf, Germany), and they are uncorrected. NMR spectroscopy was performed in CD₃OD or DMSO at room temperature using a Varian Gemini 300 MHz (¹H NMR 300 MHz, ¹³C NMR 75 MHz) and an Agilent 400 MR DDR2 (¹H NMR 400 MHz, ¹³C NMR 100 MHz). Preparative HPLC was performed using COMBIFLASH RF200 UV/VIS (Teledyne ISCO, Lincoln, NE, USA). An in-house made column was prepared by filling a cartridge with polar silica (Merck, Darmstadt, Germany) for normal phase HPLC. For reverse phase HPLC, the commercially available RediSep^® Gold C18 column (Teledyne ISCO) was used.