Syntheses of Batzelline A, Batzeline B, Isobatzelline A, and Isobatzelline B

✍ Scribed by Mercedes Alvarez; M. Antonieta Bros; Gemma Gras; Wadi Ajana; John A. Joule

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 371 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199905)1999:5<1173::aid-ejoc1173>3.0.co;2-o

✦ Synopsis

Scheme 6. Synthesis of batzelline B (1b) 18.7 mmol), and an excess of methanethiol in dry CH 2 Cl 2 (27 mL) dole 2-position proceeded smoothly and efficiently, but was stirred at 0°C for 16 h in a tightly stoppered flask. The solution interestingly, a mixture of the 1H-and 3H-indole tautomers was then poured onto ice, basified with 12  NaOH, and extracted 33 and 34 was obtained. In some runs, only the 3H-tauwith CH 2 Cl 2 . The organic extract was dried and the solvent was tomer 34 was isolated. Transformation of the unexpected evaporated to give the dithioacetal 4 (565 mg, 89%) as an oil. Ϫ tautomer into the 1H-tautomer was easily achieved by heat-IR (film): ν ˜ϭ 1534 cm Ϫ1 (s, NO 2 ), 1286 (s, NO 2 ). Ϫ 1 H NMR ing in methanol containing a trace of acid. There do not (200 MHz, CDCl 3 ): δ H ϭ 2.14 (s, 6 H, SCH 3 ), 4.06 (s, 3 H, OCH 3 ), seem to be any previous examples of the isolation of the 4.09 (s, 3 H, OCH 3 ), 5.06 (s, 1 H, CH), 7.80 (s, 1 H, 8-H), 7.99 (d, 3H-tautomer of a 2-alkylthioindole such as 34.