Total Synthesis of 7′,8′-Dihydroaigialospirol

Abstract

A highly convergent total synthesis of 7',8'-dihydroaigialospirol is described. Key steps of the synthesis include a Nozaki-Hiyama-Kishi (NHK) coupling of an iodoalkyne with an advanced phthalide-aldehyde and a remarkable one-pot acid-mediated global deprotection/spiroacetalization.

Synthesis and Biological Studies of a Triazole Analogue of Resorcylic Acid Lactone LL‐Z1640‐2

“…The vinyl stannane fragment 6 for the Stille coupling was prepared from the known 2‐deoxy‐ D ‐ribose acetonide6 ( 8 ) (Scheme ). Colvin rearrangement7 using TMS diazomethane and BuLi7c led to the known alkyne 12 8. Hydrostannylation of the terminal alkyne using tributyltin hydride and AIBN as an initiator provided the desired trans ‐vinyl stannane 6 after chromatographic separation of the minor cis ‐isomer ( cis / trans ratio ca.…”

“…[(4 S ,5 R )‐2,2‐Dimethyl‐5‐(prop‐2‐yn‐1‐yl)‐1,3‐dioxolan‐4‐yl]methanol (12): 8 To a solution of diisopropylamine (0.53 mL, 3.77 mmol) in anhydrous THF (3 mL) at –78 °C, was added n ‐butyllithium (2.0 M solution in THF, 1.57 mL, 3.14 mmol) dropwise and the resulting solution was stirred for 45 min. Trimethylsilyldiazomethane (2.0 M solution in Et 2 O, 0.78 mL, 1.57 mmol) was added dropwise to the above solution and the reaction was stirred for 30 min.…”

“…The solvent was removed under reduced pressure and the crude product was purified by silica gel column chromatography (EtOAc/hexane, 10 %) to give alkyne 12 (0.153 g, 75 %) as a yellow oil. R f = 0.79 (EtOAc, 100 %); [ α ] D 23 = +18.2 ( c = 1.05, CHCl 3 ){Lit 8. [ α ] D 20 = +17.6 ( c = 0.18, CHCl 3 )}.…”

“…R f = 0.79 (EtOAc, 100 %); [α] D 23 = +18.2 (c = 1.05, CHCl 3 ){Lit. [8] [α] D 20 = +17.6 (c = 0.18, CHCl 3 )}. IR (film): ν max = 3448, 3288, 2978, 2931, 2113 cm -1 .…”

Concise Synthesis of a Pateamine A Analogue with In Vivo Anticancer Activity Based on an Iron‐Catalyzed Pyrone Ring Opening/Cross‐Coupling

“…The crude material was purified by flash chromatography on silica gel (pentane/Et 2 O = 250/1 to 50/1) to yield the title compound as a colorless oil (2.05 g, 89%). 1 2 (3.85 mmol, 978 mg). The tube was evacuated and refilled with argon.…”