Synthesis of 4-thiofuranoid 1,2-glycals and their application to stereoselective synthesis of 4'-thionucleosides

Tetrahedron Letters

Volumn 41, Issue 17, 2000, Pages 3265-3268

  Miller, J Allen ^a   Pugh, Ashley W ^a   Ullah, G Mustafa ^a  

^a WELLCOME RESEARCH LABORATORIES   (United Kingdom)

Author keywords

2' deoxy 4' thionucleosides; 4 thio 1,2 glycals; Stereoselective addition

Indexed keywords

4 THIOFURANOID 1,2 GLYCAL; NUCLEOSIDE; UNCLASSIFIED DRUG;

ARTICLE; IODINATION; REDUCTION; STEREOCHEMISTRY; STRUCTURE ANALYSIS; SYNTHESIS;

EID: 0034701547     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(00)00366-X     Document Type: Article

References (35)

1. Cheng, J. C.; Hacksell, U.; Daves, G. D. J. Org. Chem. 1985, 50, 2778-2780; Abramski, W.; Chmielewski, M. J. Carbohydr. Chem. 1994, 13, 125-128; Halcomb, R. L.; Danishefsky, S. J. J. Am. Chem. Soc. 1989, 111, 6661-6666; Kassou, M.; Castillon, S. Tetrahedron Lett. 1994, 35, 5513-5516; Bravo, F.; Kassou, M.; Castillon, S. ibid. 1999, 40, 1187-1190.
2. Cheng, J. C.; Hacksell, U.; Daves, G. D. J. Org. Chem. 1985, 50, 2778-2780; Abramski, W.; Chmielewski, M. J. Carbohydr. Chem. 1994, 13, 125-128; Halcomb, R. L.; Danishefsky, S. J. J. Am. Chem. Soc. 1989, 111, 6661-6666; Kassou, M.; Castillon, S. Tetrahedron Lett. 1994, 35, 5513-5516; Bravo, F.; Kassou, M.; Castillon, S. ibid. 1999, 40, 1187-1190.
3. Cheng, J. C.; Hacksell, U.; Daves, G. D. J. Org. Chem. 1985, 50, 2778-2780; Abramski, W.; Chmielewski, M. J. Carbohydr. Chem. 1994, 13, 125-128; Halcomb, R. L.; Danishefsky, S. J. J. Am. Chem. Soc. 1989, 111, 6661-6666; Kassou, M.; Castillon, S. Tetrahedron Lett. 1994, 35, 5513-5516; Bravo, F.; Kassou, M.; Castillon, S. ibid. 1999, 40, 1187-1190.
4. Cheng, J. C.; Hacksell, U.; Daves, G. D. J. Org. Chem. 1985, 50, 2778-2780; Abramski, W.; Chmielewski, M. J. Carbohydr. Chem. 1994, 13, 125-128; Halcomb, R. L.; Danishefsky, S. J. J. Am. Chem. Soc. 1989, 111, 6661-6666; Kassou, M.; Castillon, S. Tetrahedron Lett. 1994, 35, 5513-5516; Bravo, F.; Kassou, M.; Castillon, S. ibid. 1999, 40, 1187-1190.
5. Cheng, J. C.; Hacksell, U.; Daves, G. D. J. Org. Chem. 1985, 50, 2778-2780; Abramski, W.; Chmielewski, M. J. Carbohydr. Chem. 1994, 13, 125-128; Halcomb, R. L.; Danishefsky, S. J. J. Am. Chem. Soc. 1989, 111, 6661-6666; Kassou, M.; Castillon, S. Tetrahedron Lett. 1994, 35, 5513-5516; Bravo, F.; Kassou, M.; Castillon, S. ibid. 1999, 40, 1187-1190.
6. Kim, C. U.; Lu, B. Y.; Martin, J. C. J. Org. Chem. 1991, 56, 2642-2647; Kim, C. U.; Misco, P. F. Tetrahedron Lett. 1992, 33, 5733-5736; Grewal, G.; Kaila, N.; Frank, R. W. J. Org. Chem. 1992, 57, 2084-2092; Kawakami, H.; Ebata, T.; Koseki, K.; Okano, K.; Matsumoto, K.; Matsushita, H. Heterocycles 1993, 36, 665-669; Wang, J.; Wurster, J. A.; Wilson, L. J.; Liotta, D. Tetrahedron Lett. 1993, 34, 4881-4884; Chow, K.; Danishefsky, S. J. Org Chem. 1990, 55, 4211-4214.
7. Kim, C. U.; Lu, B. Y.; Martin, J. C. J. Org. Chem. 1991, 56, 2642-2647; Kim, C. U.; Misco, P. F. Tetrahedron Lett. 1992, 33, 5733-5736; Grewal, G.; Kaila, N.; Frank, R. W. J. Org. Chem. 1992, 57, 2084-2092; Kawakami, H.; Ebata, T.; Koseki, K.; Okano, K.; Matsumoto, K.; Matsushita, H. Heterocycles 1993, 36, 665-669; Wang, J.; Wurster, J. A.; Wilson, L. J.; Liotta, D. Tetrahedron Lett. 1993, 34, 4881-4884; Chow, K.; Danishefsky, S. J. Org Chem. 1990, 55, 4211-4214.
8. Kim, C. U.; Lu, B. Y.; Martin, J. C. J. Org. Chem. 1991, 56, 2642-2647; Kim, C. U.; Misco, P. F. Tetrahedron Lett. 1992, 33, 5733-5736; Grewal, G.; Kaila, N.; Frank, R. W. J. Org. Chem. 1992, 57, 2084-2092; Kawakami, H.; Ebata, T.; Koseki, K.; Okano, K.; Matsumoto, K.; Matsushita, H. Heterocycles 1993, 36, 665-669; Wang, J.; Wurster, J. A.; Wilson, L. J.; Liotta, D. Tetrahedron Lett. 1993, 34, 4881-4884; Chow, K.; Danishefsky, S. J. Org Chem. 1990, 55, 4211-4214.
9. Kim, C. U.; Lu, B. Y.; Martin, J. C. J. Org. Chem. 1991, 56, 2642-2647; Kim, C. U.; Misco, P. F. Tetrahedron Lett. 1992, 33, 5733-5736; Grewal, G.; Kaila, N.; Frank, R. W. J. Org. Chem. 1992, 57, 2084-2092; Kawakami, H.; Ebata, T.; Koseki, K.; Okano, K.; Matsumoto, K.; Matsushita, H. Heterocycles 1993, 36, 665-669; Wang, J.; Wurster, J. A.; Wilson, L. J.; Liotta, D. Tetrahedron Lett. 1993, 34, 4881-4884; Chow, K.; Danishefsky, S. J. Org Chem. 1990, 55, 4211-4214.
10. Kim, C. U.; Lu, B. Y.; Martin, J. C. J. Org. Chem. 1991, 56, 2642-2647; Kim, C. U.; Misco, P. F. Tetrahedron Lett. 1992, 33, 5733-5736; Grewal, G.; Kaila, N.; Frank, R. W. J. Org. Chem. 1992, 57, 2084-2092; Kawakami, H.; Ebata, T.; Koseki, K.; Okano, K.; Matsumoto, K.; Matsushita, H. Heterocycles 1993, 36, 665-669; Wang, J.; Wurster, J. A.; Wilson, L. J.; Liotta, D. Tetrahedron Lett. 1993, 34, 4881-4884; Chow, K.; Danishefsky, S. J. Org Chem. 1990, 55, 4211-4214.
11. Kim, C. U.; Lu, B. Y.; Martin, J. C. J. Org. Chem. 1991, 56, 2642-2647; Kim, C. U.; Misco, P. F. Tetrahedron Lett. 1992, 33, 5733-5736; Grewal, G.; Kaila, N.; Frank, R. W. J. Org. Chem. 1992, 57, 2084-2092; Kawakami, H.; Ebata, T.; Koseki, K.; Okano, K.; Matsumoto, K.; Matsushita, H. Heterocycles 1993, 36, 665-669; Wang, J.; Wurster, J. A.; Wilson, L. J.; Liotta, D. Tetrahedron Lett. 1993, 34, 4881-4884; Chow, K.; Danishefsky, S. J. Org Chem. 1990, 55, 4211-4214.
12. El-Laghdach, A.; Diaz, Y.; Castillon, S. Tetrahedron Lett. 1993, 34, 2821-2822; Diaz, Y.; El-Laghdach, A.; Castillon, S. Tetrahedron 1997, 53, 10 921-10 938.
13. El-Laghdach, A.; Diaz, Y.; Castillon, S. Tetrahedron Lett. 1993, 34, 2821-2822; Diaz, Y.; El-Laghdach, A.; Castillon, S. Tetrahedron 1997, 53, 10 921-10 938.
14. For a review, see: Wnuk, S. F. Tetrahedron 1993, 49, 9877-9936. For selected leading references, see: Secrist, J. A.; Tiwari, K. N.; Riordan, J. M.; Montgomery, J. A. J. Med. Chem. 1991, 34, 2361-2366; Tiwari, K. N.; Montgomery, J. A.; Secrist, J. A. Nucleosides, Nucleotides 1995, 14, 675-686; Yoshimura, Y.; Wanatabe, M.; Satoh, H.; Ashida, N.; Ijichi, K.; Sakata, S.; Machida, H.; Matsuda, A. J. Med. Chem. 1997, 40, 2177-2183; Yoshimura, Y.; Kitano, K.; Satoh, H.; Wanatabe, M.; Miura, S.; Sakata, S.; Sasaki, T.; Matsuda, A. J. Org. Chem. 1996, 61, 822-823; Dyson, M. R.; Coe, P. L.; Walker, R. T. J. Med. Chem. 1991, 34, 2782-2786; Uenishi, J.; Motoyama, M.; Nishiyama, Y.; Wakabayashi, S. J. Chem. Soc., Chem. Commun. 1991, 1421-1422; Uenishi, J.; Takahashi, K.; Motoyama, M.; Akashi, H.; Sasaki, T. Nucleosides, Nucleotides 1994, 13, 1347-1361; Young, R. J.; Shaw-Ponter, S.; Thomson, J. B.; Miller, J. A.; Cumming, J. G.; Pugh, A. W.; Rider, P. Bioorg. Med. Chem. Lett. 1995, 5, 2599-2604.
15. For a review, see: Wnuk, S. F. Tetrahedron 1993, 49, 9877-9936. For selected leading references, see: Secrist, J. A.; Tiwari, K. N.; Riordan, J. M.; Montgomery, J. A. J. Med. Chem. 1991, 34, 2361-2366; Tiwari, K. N.; Montgomery, J. A.; Secrist, J. A. Nucleosides, Nucleotides 1995, 14, 675-686; Yoshimura, Y.; Wanatabe, M.; Satoh, H.; Ashida, N.; Ijichi, K.; Sakata, S.; Machida, H.; Matsuda, A. J. Med. Chem. 1997, 40, 2177-2183; Yoshimura, Y.; Kitano, K.; Satoh, H.; Wanatabe, M.; Miura, S.; Sakata, S.; Sasaki, T.; Matsuda, A. J. Org. Chem. 1996, 61, 822-823; Dyson, M. R.; Coe, P. L.; Walker, R. T. J. Med. Chem. 1991, 34, 2782-2786; Uenishi, J.; Motoyama, M.; Nishiyama, Y.; Wakabayashi, S. J. Chem. Soc., Chem. Commun. 1991, 1421-1422; Uenishi, J.; Takahashi, K.; Motoyama, M.; Akashi, H.; Sasaki, T. Nucleosides, Nucleotides 1994, 13, 1347-1361; Young, R. J.; Shaw-Ponter, S.; Thomson, J. B.; Miller, J. A.; Cumming, J. G.; Pugh, A. W.; Rider, P. Bioorg. Med. Chem. Lett. 1995, 5, 2599-2604.
16. For a review, see: Wnuk, S. F. Tetrahedron 1993, 49, 9877-9936. For selected leading references, see: Secrist, J. A.; Tiwari, K. N.; Riordan, J. M.; Montgomery, J. A. J. Med. Chem. 1991, 34, 2361-2366; Tiwari, K. N.; Montgomery, J. A.; Secrist, J. A. Nucleosides, Nucleotides 1995, 14, 675-686; Yoshimura, Y.; Wanatabe, M.; Satoh, H.; Ashida, N.; Ijichi, K.; Sakata, S.; Machida, H.; Matsuda, A. J. Med. Chem. 1997, 40, 2177-2183; Yoshimura, Y.; Kitano, K.; Satoh, H.; Wanatabe, M.; Miura, S.; Sakata, S.; Sasaki, T.; Matsuda, A. J. Org. Chem. 1996, 61, 822-823; Dyson, M. R.; Coe, P. L.; Walker, R. T. J. Med. Chem. 1991, 34, 2782-2786; Uenishi, J.; Motoyama, M.; Nishiyama, Y.; Wakabayashi, S. J. Chem. Soc., Chem. Commun. 1991, 1421-1422; Uenishi, J.; Takahashi, K.; Motoyama, M.; Akashi, H.; Sasaki, T. Nucleosides, Nucleotides 1994, 13, 1347-1361; Young, R. J.; Shaw-Ponter, S.; Thomson, J. B.; Miller, J. A.; Cumming, J. G.; Pugh, A. W.; Rider, P. Bioorg. Med. Chem. Lett. 1995, 5, 2599-2604.
17. For a review, see: Wnuk, S. F. Tetrahedron 1993, 49, 9877-9936. For selected leading references, see: Secrist, J. A.; Tiwari, K. N.; Riordan, J. M.; Montgomery, J. A. J. Med. Chem. 1991, 34, 2361-2366; Tiwari, K. N.; Montgomery, J. A.; Secrist, J. A. Nucleosides, Nucleotides 1995, 14, 675-686; Yoshimura, Y.; Wanatabe, M.; Satoh, H.; Ashida, N.; Ijichi, K.; Sakata, S.; Machida, H.; Matsuda, A. J. Med. Chem. 1997, 40, 2177-2183; Yoshimura, Y.; Kitano, K.; Satoh, H.; Wanatabe, M.; Miura, S.; Sakata, S.; Sasaki, T.; Matsuda, A. J. Org. Chem. 1996, 61, 822-823; Dyson, M. R.; Coe, P. L.; Walker, R. T. J. Med. Chem. 1991, 34, 2782-2786; Uenishi, J.; Motoyama, M.; Nishiyama, Y.; Wakabayashi, S. J. Chem. Soc., Chem. Commun. 1991, 1421-1422; Uenishi, J.; Takahashi, K.; Motoyama, M.; Akashi, H.; Sasaki, T. Nucleosides, Nucleotides 1994, 13, 1347-1361; Young, R. J.; Shaw-Ponter, S.; Thomson, J. B.; Miller, J. A.; Cumming, J. G.; Pugh, A. W.; Rider, P. Bioorg. Med. Chem. Lett. 1995, 5, 2599-2604.
18. For a review, see: Wnuk, S. F. Tetrahedron 1993, 49, 9877-9936. For selected leading references, see: Secrist, J. A.; Tiwari, K. N.; Riordan, J. M.; Montgomery, J. A. J. Med. Chem. 1991, 34, 2361-2366; Tiwari, K. N.; Montgomery, J. A.; Secrist, J. A. Nucleosides, Nucleotides 1995, 14, 675-686; Yoshimura, Y.; Wanatabe, M.; Satoh, H.; Ashida, N.; Ijichi, K.; Sakata, S.; Machida, H.; Matsuda, A. J. Med. Chem. 1997, 40, 2177-2183; Yoshimura, Y.; Kitano, K.; Satoh, H.; Wanatabe, M.; Miura, S.; Sakata, S.; Sasaki, T.; Matsuda, A. J. Org. Chem. 1996, 61, 822-823; Dyson, M. R.; Coe, P. L.; Walker, R. T. J. Med. Chem. 1991, 34, 2782-2786; Uenishi, J.; Motoyama, M.; Nishiyama, Y.; Wakabayashi, S. J. Chem. Soc., Chem. Commun. 1991, 1421-1422; Uenishi, J.; Takahashi, K.; Motoyama, M.; Akashi, H.; Sasaki, T. Nucleosides, Nucleotides 1994, 13, 1347-1361; Young, R. J.; Shaw-Ponter, S.; Thomson, J. B.; Miller, J. A.; Cumming, J. G.; Pugh, A. W.; Rider, P. Bioorg. Med. Chem. Lett. 1995, 5, 2599-2604.
19. For a review, see: Wnuk, S. F. Tetrahedron 1993, 49, 9877-9936. For selected leading references, see: Secrist, J. A.; Tiwari, K. N.; Riordan, J. M.; Montgomery, J. A. J. Med. Chem. 1991, 34, 2361-2366; Tiwari, K. N.; Montgomery, J. A.; Secrist, J. A. Nucleosides, Nucleotides 1995, 14, 675-686; Yoshimura, Y.; Wanatabe, M.; Satoh, H.; Ashida, N.; Ijichi, K.; Sakata, S.; Machida, H.; Matsuda, A. J. Med. Chem. 1997, 40, 2177-2183; Yoshimura, Y.; Kitano, K.; Satoh, H.; Wanatabe, M.; Miura, S.; Sakata, S.; Sasaki, T.; Matsuda, A. J. Org. Chem. 1996, 61, 822-823; Dyson, M. R.; Coe, P. L.; Walker, R. T. J. Med. Chem. 1991, 34, 2782-2786; Uenishi, J.; Motoyama, M.; Nishiyama, Y.; Wakabayashi, S. J. Chem. Soc., Chem. Commun. 1991, 1421-1422; Uenishi, J.; Takahashi, K.; Motoyama, M.; Akashi, H.; Sasaki, T. Nucleosides, Nucleotides 1994, 13, 1347-1361; Young, R. J.; Shaw-Ponter, S.; Thomson, J. B.; Miller, J. A.; Cumming, J. G.; Pugh, A. W.; Rider, P. Bioorg. Med. Chem. Lett. 1995, 5, 2599-2604.
20. For a review, see: Wnuk, S. F. Tetrahedron 1993, 49, 9877-9936. For selected leading references, see: Secrist, J. A.; Tiwari, K. N.; Riordan, J. M.; Montgomery, J. A. J. Med. Chem. 1991, 34, 2361-2366; Tiwari, K. N.; Montgomery, J. A.; Secrist, J. A. Nucleosides, Nucleotides 1995, 14, 675-686; Yoshimura, Y.; Wanatabe, M.; Satoh, H.; Ashida, N.; Ijichi, K.; Sakata, S.; Machida, H.; Matsuda, A. J. Med. Chem. 1997, 40, 2177-2183; Yoshimura, Y.; Kitano, K.; Satoh, H.; Wanatabe, M.; Miura, S.; Sakata, S.; Sasaki, T.; Matsuda, A. J. Org. Chem. 1996, 61, 822-823; Dyson, M. R.; Coe, P. L.; Walker, R. T. J. Med. Chem. 1991, 34, 2782-2786; Uenishi, J.; Motoyama, M.; Nishiyama, Y.; Wakabayashi, S. J. Chem. Soc., Chem. Commun. 1991, 1421-1422; Uenishi, J.; Takahashi, K.; Motoyama, M.; Akashi, H.; Sasaki, T. Nucleosides, Nucleotides 1994, 13, 1347-1361; Young, R. J.; Shaw-Ponter, S.; Thomson, J. B.; Miller, J. A.; Cumming, J. G.; Pugh, A. W.; Rider, P. Bioorg. Med. Chem. Lett. 1995, 5, 2599-2604.
21. For a review, see: Wnuk, S. F. Tetrahedron 1993, 49, 9877-9936. For selected leading references, see: Secrist, J. A.; Tiwari, K. N.; Riordan, J. M.; Montgomery, J. A. J. Med. Chem. 1991, 34, 2361-2366; Tiwari, K. N.; Montgomery, J. A.; Secrist, J. A. Nucleosides, Nucleotides 1995, 14, 675-686; Yoshimura, Y.; Wanatabe, M.; Satoh, H.; Ashida, N.; Ijichi, K.; Sakata, S.; Machida, H.; Matsuda, A. J. Med. Chem. 1997, 40, 2177-2183; Yoshimura, Y.; Kitano, K.; Satoh, H.; Wanatabe, M.; Miura, S.; Sakata, S.; Sasaki, T.; Matsuda, A. J. Org. Chem. 1996, 61, 822-823; Dyson, M. R.; Coe, P. L.; Walker, R. T. J. Med. Chem. 1991, 34, 2782-2786; Uenishi, J.; Motoyama, M.; Nishiyama, Y.; Wakabayashi, S. J. Chem. Soc., Chem. Commun. 1991, 1421-1422; Uenishi, J.; Takahashi, K.; Motoyama, M.; Akashi, H.; Sasaki, T. Nucleosides, Nucleotides 1994, 13, 1347-1361; Young, R. J.; Shaw-Ponter, S.; Thomson, J. B.; Miller, J. A.; Cumming, J. G.; Pugh, A. W.; Rider, P. Bioorg. Med. Chem. Lett. 1995, 5, 2599-2604.
22. For a review, see: Wnuk, S. F. Tetrahedron 1993, 49, 9877-9936. For selected leading references, see: Secrist, J. A.; Tiwari, K. N.; Riordan, J. M.; Montgomery, J. A. J. Med. Chem. 1991, 34, 2361-2366; Tiwari, K. N.; Montgomery, J. A.; Secrist, J. A. Nucleosides, Nucleotides 1995, 14, 675-686; Yoshimura, Y.; Wanatabe, M.; Satoh, H.; Ashida, N.; Ijichi, K.; Sakata, S.; Machida, H.; Matsuda, A. J. Med. Chem. 1997, 40, 2177-2183; Yoshimura, Y.; Kitano, K.; Satoh, H.; Wanatabe, M.; Miura, S.; Sakata, S.; Sasaki, T.; Matsuda, A. J. Org. Chem. 1996, 61, 822-823; Dyson, M. R.; Coe, P. L.; Walker, R. T. J. Med. Chem. 1991, 34, 2782-2786; Uenishi, J.; Motoyama, M.; Nishiyama, Y.; Wakabayashi, S. J. Chem. Soc., Chem. Commun. 1991, 1421-1422; Uenishi, J.; Takahashi, K.; Motoyama, M.; Akashi, H.; Sasaki, T. Nucleosides, Nucleotides 1994, 13, 1347-1361; Young, R. J.; Shaw-Ponter, S.; Thomson, J. B.; Miller, J. A.; Cumming, J. G.; Pugh, A. W.; Rider, P. Bioorg. Med. Chem. Lett. 1995, 5, 2599-2604.
23. (a) Synthesis: Branalt, J.; Kvarnstrom, I.; Niklasson, G.; Svensson, S. C. T.; Classon, B.; Samuelsson, B. J. Org. Chem. 1994, 59, 1783-1788; Branalt, J.; Kvarnstrom, I.; Svensson, S. C. T.; Classon, B.; Samuelsson, B. J. Org. Chem. 1994, 59, 4430-4432;
24. (a) Synthesis: Branalt, J.; Kvarnstrom, I.; Niklasson, G.; Svensson, S. C. T.; Classon, B.; Samuelsson, B. J. Org. Chem. 1994, 59, 1783-1788; Branalt, J.; Kvarnstrom, I.; Svensson, S. C. T.; Classon, B.; Samuelsson, B. J. Org. Chem. 1994, 59, 4430-4432;
25. (b) Addition reactions: Haraguchi, K.; Nishikawa, A.; Sasakura, E.; Tanaka, H.; Nakamura, K. T.; Miyasaka, T. Tetrahedron Lett. 1998, 39, 3713-3716.
26. O'Neil, I. A.; Hamilton, K. M.; Miller, J. A.; Young, R. J. Synlett. 1995, 151-152.
27. Dyson, M. R.; Coe, P. L.; Walker, R. T. Carbohydr. Res. 1991, 216, 237-238; Tiwari, K. N.; Montgomery, J. A.; Secrist, J. A. Nucleosides, Nucleotides 1993, 12, 841-846.
28. Dyson, M. R.; Coe, P. L.; Walker, R. T. Carbohydr. Res. 1991, 216, 237-238; Tiwari, K. N.; Montgomery, J. A.; Secrist, J. A. Nucleosides, Nucleotides 1993, 12, 841-846.
29. Our prime focus was a β-selective synthesis of 1-(2′-deoxy-4′-thio-β-D-erythro-pentofuranosyl)-5-ethyluracil and related structures as anti-herpes agents - see: Rahim, S. G.; Trivedi, N.; Bogunovic-Batchelor, M. V.; Hardy, G. W.; Mills, G.; Selway, J. W. T.; Littler, E.; Coe, P.; Basnak, I.; Whale, R. F.; Walker, R. T. J. Med. Chem. 1996, 39, 789-795.
30. Bellon, L.; Barascut, J.-L.; Limpach, J.-L. Nucleosides, Nucleotides 1992, 11, 1467-1479.
31. Ewing, D. F.; Mackenzie, G. Nucleosides, Nucleotides 1996, 15, 809-820.
32. 2S requires: 312.
33. 2SI): C, H, N.
34. 2Ph), 6.35 (dd, J=6 Hz, 4Hz, 1H, 1′-CH), 7.2-7.4 (m, 10H, 2×Ph), 7.98 (s, 1H, C-6 CH), 9.0 (bs, 1H, NH).
35. 4S): C, H, N.