An Efficient and Practical Total Synthesis of Sauristolactam

An unprecedented deoxygenation protocol of benzylic alcohols using bis(1-benzotriazolyl)methanethione

“…Red crystals; 1 H NMR (300 MHz, CDCl 3 ): d 8.02 (d,J ¼ 7.8 Hz,1H),3H),1H),4.38 (s,1H),8H), 2.03 (d, J ¼ 7.2 Hz, 3H) ppm; 13 C NMR (75 MHz, CDCl 3 ): d 146. 2,131.6 (2C),126.7,123.5,119.9,110.4,87.2,69.0,68.9,68.8,68.7,68.2,68.0,67.9,67.8,66.6,66.4,55.7,55.6,ethane (32). Red crystals, MS: m/z 332 [M + H] + ; 1 H NMR (300 MHz, CDCl 3 ): d 7.84 (d,J ¼ 3.3 Hz,2H),7.34 (d,J ¼ 3.3 Hz,2H),1H),4.38 (s,1H),4.32 (s,1H),7H), 2.06 (d, J ¼ 6.6 Hz, 3H) ppm; 13 C NMR (75 MHz, CDCl 3 ) : d 143.8, 126.0 (2C), 118.1 (2C), 88.0, 68.9, 68.7, 68.5, 68.4, 68.0, 67.9, 67.8, 67.6, 66.6, 66.5, 62.6, 62.5 ppm.…”

The isolation-biological activities (2014–2022), bio, semi, total synthesis (1978–2022) and SAR studies of a potential naturally engineered scaffold aristolactam

“…In 2011, Heo and co-workers accomplished the total synthesis of sauristolactam by employing a Suzuki–Miyaura coupling/Aldol condensation cascade reaction as a key step (Scheme 32). 92 In their previous report, regioselective mono-demethylation of 3,4-dimethoxy aristolactam with HBr was not very effective and produced only 11% of the desired sauristolactam 65 along with 19% of other aristolactam 238 (Scheme 31). In this report, the authors targeted a practical method for the synthesis of sauristolactam.…”

Recent Applications of Phosphane-based Palladium Catalysts in Suzuki-Miyaura Reactions Involved in Total Syntheses of Natural Products

“…A year later, an efficient and practical synthesis of the naturally-occurring alkaloid sauristolactam (32) was accomplished by Heo and co-workers on the basis of the retrosynthesis shown in Scheme 27 in which a S.-M. coupling/aldol condensation cascade reaction involving boronic acid A26 and isoindolone B29 was a key step. [108] Scheme 27. Retrosynthesis of sauristolactam (32) As shown in entry 30 of Table 2, the reaction of B29 with A26, which was performed in a mixture of toluene and EtOH under microwave irradiation in the presence of 4 mol% Pd(PPh3)4 and 3 equiv of Cs2CO3, provided 32 in 80% yield.…”

“…Retrosynthesis of sauristolactam (32) As shown in entry 30 of Table 2, the reaction of B29 with A26, which was performed in a mixture of toluene and EtOH under microwave irradiation in the presence of 4 mol% Pd(PPh3)4 and 3 equiv of Cs2CO3, provided 32 in 80% yield. [108] In 2010, Choshi, Hibino and co-workers described a total synthesis of the neuronal cell protecting carbazole alkaloid carbazomadurin A (33) in which the (E)-alkenyl side chain at the C1 position of carbazole was introduced by the Pd(PPh3)4-catalyzed reaction of pinacol boronate A27 with triflate B30 (entry 31, Table 2). [109] Unfortunately, the detailed experimental conditions of the coupling, which was carried out in DMF using Na2CO3 as base to provided compound C27 in almost quantitative yield, were not In 2012, Fürstner and co-workers reported the first total synthesis of the structurally challenging and biologically highly promising antimitotic agent leiodermatolide (34).…”