1: With potassium tert-butylate in tetrahydrofuran T=-78 - 20°C; Condensation; 2: With acetic acid T=20°C; Elimination; 1.5 h;

1: 2-(dimethoxyphosphoryl)-4,5-dimethyl-2H-1,3-dithiole With potassium tert-butylate in tetrahydrofuran T=-78°C; Wittig-Horner reaction; 1 h; Inert atmosphere; 2: 2-piperidino-4-methyl-1,3-dithiolium hexafluorophosphate in tetrahydrofuran T=-78°C; Wittig-Horner reaction; 1 h; Inert atmosphere;

in tetrahydrofuran 12 h; Ambient temperature; Yield given;