Stereoselective Syntheses of Highly Substituted Tetrahydrofurans based on Matteson Homologations

Deprotonated trimethylsilylethanol is an excellent nucleophile for Matteson homologations. It can be introduced in high yields and the products are stable under the usual basic reaction conditions. After two further homologation steps, the protective group is automatically cleaved off via a six-membered ring O-B coordination, providing highly substituted tetrahydrofurans.