Cyclization of 1,6-enynes with allylic chromate species

Organic Letters

Volumn 4, Issue 16, 2002, Pages 2795-2797

  Nishikawa, Toshihiro ^a   Shinokubo, Hiroshi ^a   Oshima, Koichiro ^a  

^a KYOTO UNIVERSITY   (Japan)

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ARTICLE;

EID: 0042691413     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol026362o     Document Type: Article

References (14)

1. (a) Fürstner, A. Chem. Rev. 1999, 99, 991.
2. (b) Saccomano, N. A. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Eds.; Pergamon Press: New York, 1991; Vol. 1, Chapter 1.6, p 173.
3. (c) Takai, K. In Encyclopedia of Reagents for Organic Synthesis; Paquette, L. A., Ed.; Wiley: New York, 1995; p 1266.
4. (a) Kauffmann, T.; Hamsen, A.; Beirich, C. Angew. Chem., Int. Ed. Engl. 1982, 21, 144.
5. (b) Kauffmann, T.; Möller, T.; Rennefeld, H.; Welke, S.; Wieschollek, R. Angew. Chem., Int. Ed. Engl. 1985, 24, 348.
6. Addition of diallylchromium phosphine complex toward alkynes was reported, see: Betz, P.; Jolly, P. W.; Krüger, C.; Zakrzewski, U. Organometallics 1991, 10, 3520.
7. Nishikawa, T.; Kakiya, T.; Shinokubo, H.; Oshima, K. J. Am. Chem. Soc. 2001, 123, 4629.
8. Allylic Grignard reagents in THF are easily prepared according to the reported procedure. Lipshutz, B. H.; Hackmann, C. J. Org. Chem. 1994, 59, 7437.
9. 3 was dissolved in THF upon treatment with Grignard reagents.
10. Protonation of alkylchromium species is normally inefficient. This fact suggests that 2a is an ate complex type species.
11. (a) Hojo, M.; Sakuragi, R.; Okabe, S.; Hosomi, A. Chem. Commun. 2001, 357.
12. (b) Hojo, M.; Sakata, K.; Ushioda, N.; Watanabe, T.; Hosomi, A. Organometallics 2001, 20, 5014.
13. (c) Hojo, M.; Sakata, K.; Maimaiti, X.; Ueno, J.; Nishikori, H.; Hosomi, A. Chem. Lett. 2002, 142.
14. 3 (4.0 mg, 0.025 mmol) at 0°C. After the solution was stirred for 20 min, 1a (90 mg, 0.5 mmol) was introduced and the mixture was stirred for 5 h at 40°C. The reaction mixture was then cooled to 0°C. To the mixture were added allyl bromide (2.25 mmol) and CuCN·2LiCl (0.1 mmol). After being stirred for another 45 min, the mixture was poured into 1 M HCl and extracted with ether. The organic layers were dried and concentrated. Purification by chromatography afforded 5d (121 mg, 0.41 mmol) in 82% yield.