Chemistry of electron-rich conjugated polyenes. Part 4. A simple and general synthesis of 1-alkoxy-3-trimethylsilyloxybuta-1,3-dienes

Abstract

Acid-catalysed addition of ketens to 1-alkoxyalkenes yields alkoxycyclobutanones, which on trimethylsilylation under basic conditions give trans-3-alkoxy-1-trimethylsilyloxycyclobutenes. These derivatives undergo electrocyclic ring opening below 100 °C to give the title compounds in which the 1-alkoxy-group and the 4-substituent are trans. Some reactions to illustrate the synthetic application of these highly functionalized electron-rich butadienes are given.