1: 2,2,4,5,8,8-hexamethyl-6-methylene-3,7-dioxa-2,8-disilanon-4-ene With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: methyl iodide in tetrahydrofuran; hexane T=-78 - 20°C;

T=120°C; Diels-Alder reaction; 4 h;