Synthetic Studies of Halichondrin B, an Antitumor Polyether Macrolide Isolated from a Marine Sponge. 4. Synthesis of the C37-C54 Subunit via Stereoselective Construction of Three Consecutive J, K, and L Rings - Horita, K; Sakurai, Y; Nagasawa, M; Maeno, K; Hachiya, S; Yonemitsu, O (Synlett, 1994)