Total syntheses of several ergoline-type alkaloids, (±)-agroclavine (21), (±)-agroclavine I (24), (±)-fumigaclavine B (28), and (±)-lysergene (33), were accomplished via a route involving reductive photoxyclization of the enamide 5 followed by oxidative cleavage of the dihydrofuran ring.
通过烯酰胺 5 的还原性光环化以及二氢呋喃环的氧化裂解路线,完成了几种麦角林型生物碱的全合成,包括 (±)-agroclavine (21)、(±)-agroclavine I (24)、(±)-fumigaclavine B (28) 和 (±)-lysergene (33)。
Solving a Mystery with Classical and Dual Photoredox Catalysis: Application of Nickel in the Synthesis of Ergot Alkaloids
A short synthesis of the ergotalkaloid lysergene and a formal total synthesis of lysergic acid diethylamide (LSD) under the avoidance of palladium and including two nickel-catalyzed steps instead have been developed. A key intermediate of this approach has already been reported by Hendrickson et al. in 2004 (Hendrickson, J.B. et al. Org. Lett. 2004, 6, 3–5), yet the spectral data do not match, adding