Studies toward the Total Synthesis of Griseoviridin

The synthesis of bis-macrolactam 5 as an advanced intermediate for the projected total synthesis of griseoviridin (1) 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 5 and deprotection gave griseoviridin analog 36 in 32% yield.