Syntheses of Substituted 6-Hydroxyhexenoic Acids and Related Tetrahydrofuran Systems by Metallocene-Template Directed 1,4-Selective Coupling of 1,3-Butadiene with Carbonyl Compounds - Erker, Gerhard; Berlekamp, Martin; Lopez, Luis; Grehl, Matthias; Schönecker, Bruno; Krieg, Reimar (Synthesis, 1994)