Stereoselective synthesis of dienyl phosphonates via extended tethered ring-closing metathesis.
Allylphosphonates of allylic alcohols were converted to conjugated dienyl phosphonates in a one-flask reaction, comprising a ring-closing metathesis (RCM), a base-induced ring-opening, and an alkylation. The ring-opening proceeds with very high diastereoselectivity, giving exclusively the (1Z,3E)-configured dienes. Single diastereomers and mixtures of diastereomers can be used as starting materials without noticeable effect on the diastereoselectivity of the sequence.
Institut fuer Chemie (Organische Synthesechemie), Universitaet Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany. bernd.schmidt@uni-potsdam.de
Bernd
B
Schmidt
Oliver
O
Kunz