Sila-Riechstoffe und Riechstoffe-Isostere, 10. Mitt. Ein neuer Weg zu Sila-β-Jonon

Preparation of sila--ionone (14) was possible by a novel route with yields nearly 5 times higher than before¹, with the formerly unknown 1,1,3-trimethyl-1-silacyclohexanone-2 (6) as a key substance. The nine reaction steps may be seen from Scheme 1. 2-Ethinyl-1,1,3-trimethyl-1-silacyclohexan-2-ol (7) could not be dehydrated to give the analogous silacyclohexene derivative9. But dehydration was successful in the case of 2-(1-butin-3-ol) substituents; here only the ring but not the chain hydroxyl group was eliminated.