6.1. C1-C15 Subunit Synthesis 3066 6.2. C1-C21 Subunit Synthesis 3066 6.3. C27-C35 Subunit Synthesis 3066 6.4. C37-C51 Subunit Synthesis 3067 7. Synthetic Work toward Halichondrin B by Burke 3068 7.1. C1-C15 Subunit Synthesis 3068 7.2. C14-C22 Subunit Synthesis 3069 7.3. Synthesis of the C22-C34(36) Subunit 3070 7.4. Synthesis of the C38-C54 Subunit 3072 7.5. Subunit Couplings 3073 8. The Discovery and Development of E7389 3073 8.1. Preliminary SAR Studies 3074 8.2. Synthesis and SAR of ER-076349, E7389, and Analogues 3075