Synthesis of the 1-Phenethyltetrahydroisoquinoline Alkaloids (+)-Dysoxyline, (+)-Colchiethanamine, and (+)-Colchiethine

Abstract

Asymmetric total syntheses of the 1-phenethyl-1,2,3,4-tetrahydroisoquinoline alkaloids (+)-dysoxyline (1), (+)-colchiethanamine (2), and (+)-colchiethine (3) are described. In the synthetic routes, coupling of a key, enatiomerically pure 1-(sulfonylmethyl)tetrahydroisoquinoline with aromatic aldehydes, performed by using the Julia-Kocienski reaction, afforded the corresponding 1-(β-styryl)-substituted tetrahydroisoquinolines with complete retention of the absolute configuration at the C1 carbon atom. Functionalization of the products generated in these processes by using four- or five-step sequences gave the target alkaloids 1-3.

Succinct Syntheses of Methopholine, (±)‐Homolaudanosine, and (±)‐Dysoxyline via Metal‐free One‐Pot Double Alkylation on 1‐Methyl‐3,4‐dihydroisoquinolines

“…All of three natural products were obtained in good yields. Compared with the literature precedents, [19][20][21][22][23][24][25][26][27][28] our synthetic approach for these natural products is unique and concise, requiring only two steps from DHIQ 1d.…”

“…Data are consistent with those reported in the literature. 27 Synthesis of (AE)-Homolaudanosine. To a solution of 4j (50.0 mg, 0.101 mmol) in methanol (1 mL) was added NaBH 4 (11.0 mg, 0.291 mmol) at 0 C. The resulting mixture was stirred at 0 C for 10 min, quenched with water, and then extracted with EtOAc (2 X 25 mL).…”

“…17,18 Methopholine is an opioid analgesic more effective than codeine. [19][20][21][22] Homolaudanosine [23][24][25] and dysoxyline, [26][27][28] structurally very similar to methopholine, were isolated from Dysoxylum lenticellare showing molluscicidal activities. 29 3,4-Dihydroisoquinoline (DHIQ) is a well-known precursor for the syntheses of diverse THIQs.…”

“…Methopholine is an opioid analgesic more effective than codeine . Homolaudanosine and dysoxyline, structurally very similar to methopholine, were isolated from Dysoxylum lenticellare showing molluscicidal activities …”

One-Pot Synthesis of 2-Benzyl-3,4-dihydro-2H-isoquinolin-1-ones Catalyzed by CuCl2

“…Reaction mechanism of "one-pot" synthesis[V(石油醚)∶V(乙酸乙酯)＝10∶1], 最后得到 0.14 g 浅 黄色液体 2-苄基-3,4-二氢异喹啉-1-酮(4a), 产率为 60%. 1 H NMR (500 MHz, CDCl 3 ) δ: 8.18 (d, J＝7.6 Hz, 1H), 7.45 (t, J＝6.9 Hz, 1H), 7.39(d, J＝7.5 Hz, 1H), 7.36(d, J＝4.5 Hz, 2H), 7.31 (s, 1H), 7.19(d, J＝7.4 Hz, 1H), 4.83 (s, 2H), 3.51 (s, 1H), 2.96 (s, 1H); 13 C NMR (125 MHz, CDCl 3 ) δ: 164.…”