Stereoselective reduction of conjugated homopropargylic alcohols 1 followed by an elimination reaction, allows an efficient approach to stereodefined (E,E,E)-chlorotrienes. The interest of these chlorotrienes was illustrated by a stereocontrolled synthesis of navenone B and all E conjugated polyenes (trienes, tetraenes and hexaenes). (C) 1997 Published by Elsevier Science Ltd.