Total synthesis of 1-oxomiltirone via Suzuki coupling

Abstract

Abietane diterpenes and miltirone series have shown important activities and for medical purposes in order to achieve the total synthesis of 1-oxomiltrone 1 and miltirone 4, a versatile intermediate 6 was found. The compound 6 could be used as a precursor A-B-C rings with different oxidative degrees in selected abietane diterpenes when synthesized through high yield Suzuki reaction and subsequent cyclization, and total synthesis of 1-oxomiltirone (1) has been achieved.

Catalytic Asymmetric Formal Total Synthesis of (−)-Triptophenolide and (+)-Triptolide

“…Our synthesis commenced with coupling reaction of arylboronic acid 8 [15]. Commercially available 3-Me-cyclohexenone was treated with trifluoroacetic palladium and ( s )- t -BuPyOX ligand in heterogeneous solvent and 9 was isolated in moderate ee and 73 % yield [32].…”

“…These findings have, in return, promoted the development of efficient synthesis strategy. We seek to discover new lead compounds, especially from nature terpenoids, for the development of anticancer drug [15–17]. Hence, TP is a valuable target for us to investigate SAR of tri-epoxide.…”

Total Synthesis of Natural Products using Gold Catalysis

“…The abietane diterpenes have profound biological activities. These diterpenoids majorly display antibacterial, anti‐inflammatory, antioxidant, and cytotoxicity values [161,162] . The structural feature of the abietane diterpenoids is the presence of fused [6‐6‐6] tricyclic ring structures [163] .…”

Total Synthesis of 1-Oxomiltirone and Arucadiol

“…14,15 We also showed that the Au-catalyzed reaction on diynals and enynals can be proceeded selectively by [4+2]-benzannulation or [3+2]-cycloaddition to give the corresponding 6-6-6-or 6-7-5-tricyclic skeleton depending the reaction conditions. 16 Taking into account the efficiency and capability to construct the complex tricyclic skeleton of this process, we report herein the total synthesis of 1-oxomiltirone 7,8 and arucadiol 17 ( Figure 1) by using [4+2]-benzannulation catalyzed by AuBr 3 or Cu(OTf) 2 . We envisioned that the 6-6-6-fused ring may prepare efficiently from key intermediate diynal 6 via only one cycloaddition step.…”

“…Due to its complex structural characteristics as well as the interesting biological activity, synthesis of abietane natural products has been the object of several research groups. [5][6][7] Two main strategies have been applied for the synthesis of these compounds: (1) semisynthesis starting from natural product was performed to introduce the required functional group, 8 and (2) the 6-6-6-tricyclic core by cycloaddition/cyclization has been constructed.…”