SEARCH Articles Figures Tables Hajos-Eder-Sauer-Wiechert Hajos-Parrish-Eder-Sauer-Wiechert cyclization Hajos-Parrish-Eder-Sauer-Wiechert process Hajos-Parrish-Eder-Sauer-Wiechert synthesis Hajos-Parrish-Wiechert-Eder-Sauer reaction Sauer