Studies toward the Total Synthesis of Griseoviridin

The synthesis of bis-macrolactam <b>5</b> as an advanced intermediate for the projected total synthesis of griseoviridin (<b>1</b>) has been achieved via intramolecular Suzuki-Miyaura coupling (>70% yield). Further key steps were the construction of the C(17)-C(18) bond by a SmI₂-mediated Barbier-type coupling, the establishment of the C(18) stereocenter by a diastereoselective Narasaka-Prasad reduction, and an electrophilic sulfur transfer to establish the S(1)-C(2) bond. DMP oxidation of <b>5</b> and deprotection gave griseoviridin analog <b>36</b> in 32% yield.