1: (3-bromo-3,3-difluoroprop-1-ynyl)(triisopropyl)silane With indium in tetrahydrofuran; water T=20°C; Metallation; 2: formaldehyd in tetrahydrofuran; water T=20°C; Addition; 12 h; Further stages.;

1: (3-bromo-3,3-difluoroprop-1-ynyl)(triisopropyl)silane With indium in tetrahydrofuran; water T=5°C; 8 h; sonication; 2: formaldehyd in tetrahydrofuran; water 17 h; sonication;

1.1: n-BuLi / hexane; tetrahydrofuran / -78 °C 1.2: hexane; tetrahydrofuran / 9 h / -78 - 20 °C 2.1: indium / tetrahydrofuran; H2O / 8 h / 5 °C / sonication 2.2: tetrahydrofuran; H2O / 17 h / sonication View Scheme