Shotgun process: A practical treatment for simultaneous multiple reactions

Synlett

Volumn , Issue 5, 2000, Pages 599-602

  Orita, Akihiro ^a   Nagano, Yoshifumi ^a   Nakazawa, Koichi ^a   Otera, Junzo ^a  

^a OKAYAMA UNIVERSITY OF SCIENCE   (Japan)

Author keywords

Acetylation; Allylation; Diels Alder reaction; Sc(OTf)3

Indexed keywords

REAGENT;

ARTICLE; CATALYST; CHEMICAL REACTION; CHEMICAL STRUCTURE; REACTION ANALYSIS;

EID: 0034035218     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article

References (16)

1. Chen, J.; Otera, J. Angew. Chem. Int. Ed. Engl. 1998, 37, 91. Chen, J.; Otera, J. Tetrahedron Lett. 1998, 39, 1767. Chen, J.; Sakamoto, K.; Orita, A. Otera, J. Tetrahedron 1998, 54, 8411.
2. Chen, J.; Otera, J. Angew. Chem. Int. Ed. Engl. 1998, 37, 91. Chen, J.; Otera, J. Tetrahedron Lett. 1998, 39, 1767. Chen, J.; Sakamoto, K.; Orita, A. Otera, J. Tetrahedron 1998, 54, 8411.
3. Chen, J.; Otera, J. Angew. Chem. Int. Ed. Engl. 1998, 37, 91. Chen, J.; Otera, J. Tetrahedron Lett. 1998, 39, 1767. Chen, J.; Sakamoto, K.; Orita, A. Otera, J. Tetrahedron 1998, 54, 8411.
4. Kobayashi, S.; Araki, M.; Hachiya, I. J. Org. Chem. 1994, 59, 3758. Kobayashi, S.; Hachiya, I.; Araki, M.; Ishitani, H. Tetrahedron Lett. 1993, 34, 3755.
5. Kobayashi, S.; Araki, M.; Hachiya, I. J. Org. Chem. 1994, 59, 3758. Kobayashi, S.; Hachiya, I.; Araki, M.; Ishitani, H. Tetrahedron Lett. 1993, 34, 3755.
6. Ishihara, K.; Kubota, M.; Kurihara, H.; Yamamoto, H. J. Org. Chem. 1996, 61, 4560. Ishihara, K.; Kubota, M.; Kurihara, H.; Yamamoto, H. J. Am. Chem. Soc. 1995, 117, 4413.
7. Ishihara, K.; Kubota, M.; Kurihara, H.; Yamamoto, H. J. Org. Chem. 1996, 61, 4560. Ishihara, K.; Kubota, M.; Kurihara, H.; Yamamoto, H. J. Am. Chem. Soc. 1995, 117, 4413.
8. The reactions proceed well with lower catalyst concentrations. However, the 40 mol% catalyst loading was employed for comparison with the shotgun process: see ref. 6.
9. Hachiya, I.; Kobayashi, S. J. Org. Chem. 1993, 58, 6958. Kobayashi, S.; Wakabayashi, T.; Oyamada, H. Chem Lett. 1997, 831.
10. Hachiya, I.; Kobayashi, S. J. Org. Chem. 1993, 58, 6958. Kobayashi, S.; Wakabayashi, T.; Oyamada, H. Chem Lett. 1997, 831.
11. With lower catalyst concentrations, the yield of 5 was not satisfactory. In particular, the acetylalion of the homoallyl alcohol stayed below 50% conversion.
12. 2 since tetraallyltin reacts with aldehyde even in the presence of water and thus the precise yield should be determined without aqueous workup.
13. 1H NMR spectra.
14. 2O.
15. 3 to furnish complex products which are difficult to identify. These unfavorable side reactions are responsible for the retardation.
16. 2O (2 equiv) was stirred for 12 h at 0 °C and, then, 2 (2 equiv) and dimethyl maleate (1 equiv) were added to this solution. The reaction mixture was stirred for 12 h at 0 °C to furnish the Diels-Alder product only in 38% yield with the recovered dimethyl maleate (57%). No explanation for the acceleration of the allylation, however, is available at the moment.