Novel syntheses of camptothecin alkaloids. Part 2. Concise synthesis of (S)-camptothecins

Tetrahedron Letters

Volumn 37, Issue 32, 1996, Pages 5683-5686

  Fortunak, Joseph M D ^a   Kitteringham, John ^a   Mastrocola, Antonietta R ^a   Mellinger, Mark ^a   Sisti, Nicolas J ^a   Wood, Jeffery L ^a   Zhuang, Zhi Ping ^a  

^a NONE

Author keywords

[No Author keywords available]

Indexed keywords

CAMPTOTHECIN DERIVATIVE; TOPOTECAN;

ARTICLE; CHIRALITY; DRUG SYNTHESIS; REACTION ANALYSIS; TECHNIQUE;

EID: 0030570853     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/0040-4039(96)01205-1     Document Type: Article

References (31)

1. 1. Refer to the immediately preceding communication.
2. 2. a) cf. Seebach, D. Angew. Chem. Int'l. Ed. Engl. 1990, 29, 1320 and quoted refs.;
3. b) Blaser, D.; Ko, S.Y.; Seebach, D. J. Org. Chem. 1991, 56, 6230;
4. c) Seebach, D.; et al. Liebigs Ann. 1989, 1215;
5. d) Blaser, D.; Seebach, D. Liebigs Ann. 1991, 1067;
6. e) Seebach, D.; Burger, H.M.; Schickli, C.P. Liebigs Ann. 1991, 669;
7. f) Suzuki, K.; Seebach, D. Liebigs Ann. 1992, 51.
8. 3. Previous asymmetric syntheses of camptothecin: a) Corey, E.J.; Crouse, D.N.; Anderson, J.E. J. Org. Chem. 1975, 40, 2140;
9. b) Wani, M.C.; Nicholas, Q.W.; Wall, M.E. J. Med. Chem. 1987, 30, 2317;
10. c) Ejima, A.; Terasawa, H.; Sugimori, M.; Tagawa, H. J. Chem. Soc. Perkin Trans. 1, 1990, 27; Ejima, A.; Terasawa, H.; Sugimori, M.; Tagawa, H. Tetrahedron Lett. 1989, 30, 2639;
11. c) Ejima, A.; Terasawa, H.; Sugimori, M.; Tagawa, H. J. Chem. Soc. Perkin Trans. 1, 1990, 27; Ejima, A.; Terasawa, H.; Sugimori, M.; Tagawa, H. Tetrahedron Lett. 1989, 30, 2639;
12. d) Comins, D.L.; Baevsky, M.F.; Hong, H. J. Am. Chem. Soc. 1992, 114, 10971; Comins, D.L.; Salvador, J.M. Tetrahedron Lett. 1993, 34, 801;
13. d) Comins, D.L.; Baevsky, M.F.; Hong, H. J. Am. Chem. Soc. 1992, 114, 10971; Comins, D.L.; Salvador, J.M. Tetrahedron Lett. 1993, 34, 801;
14. e) Curran, D.P.; Bo, S.-B.; Josien, H. Angew. Chem. Int'l. Ed. Engl. 1995, 54, 2683 and refs. cited;
15. f) Fang, F.G.; Xie, S., Lowery, M.W.; J. Org. Chem. 1994, 59, 6142.
16. 4. Glyoxal-1,1-dimethyl acetal was obtained from the Aldrich Corp., alternatively this may be conveniently prepared according to references 5.
17. 5. a) Stambouli, A.; et al. Bull. Soc. Chim. Fr. 1988, 95;
18. b) Chastrette, F.; et al. Synth. Commun. 1988, 18, 1343.
19. 6. Purchased from Chiron Laboratories, A.S. The chiral dioxolanone may also be conveniently prepared from (R)-2-hydroxybutyric acid similarly to the description in reference 7.
20. 7. Krohn, K.; Hamann, I. Liebigs. Ann. 1988, 949.
21. 8. It is well known that diastereoselectivity at carbon 5 of the dioxolanone ring is nearly always very high in alkylations of this sort; however, stereoselectivity at other carbon centers is usually poor, cf. refs. 4.
22. 1H NMR using shift reagents showed approximately 200:1 for the (R)-vs. (S)-stereochemistry at carbon 5. Comparison with an authentic sample of the (2S,5R)-trans-dioxolanone as the minor product from the reaction (ref. 6) showed that levels were below the detectable limit by either NMR or GC analysis.
23. b) (R)-2-hydroxybutyric acid was prepared from the corresponding amino acid, cf. Mori, K.; Sasaki, M.; Tamada, S.; Suguro, T.; Masuda, S. Tetrahedron 1979, 35, 1601.
24. 10. A reference sample of 9 was prepared by isolation and repeated recrystallization. After determination of nominal absolute purity for this material the solution yields were determined by HPLC analysis on a weight/weight basis relative to standard solutions of the reference sample.
25. 11. Wani, M.C.; Campbell, H.F.; Brine, G.A.; Kepler, J.A.; Wall, M.E.; Levine, S.G. J. Am. Chem. Soc. 1972, 94, 3631.
26. 12. Kimura, T.; Takai, M.; Masui, Y.; Morikawa, T.; Sakakibara, S. Biopolymers 1981, 20, 1823.
27. 13. Meyers, A.I. et al. J. Org. Chem. 1974, 38, 1973.
28. 14. Rama Rao, A.V.; Yadav, J.S.; Valluri, M. Tetrahedron Lett. 1994, 35, 3613.
29. 15. Authentic samples of (S)-10-methoxycamptothecin were obtained from Camptotheca acuminata (Sino-American Tianjin SK&F Labs Ltd., Tianjin, China). Also cf. Lin, L.-T.; Chao, T.-Y.; Hsu, J.-S. Hva Hsueh Hsueh Pao, 1977, 55, 277; Chem. Abstr. 1978, 89, 22078S.
30. 15. Authentic samples of (S)-10-methoxycamptothecin were obtained from Camptotheca acuminata (Sino-American Tianjin SK&F Labs Ltd., Tianjin, China). Also cf. Lin, L.-T.; Chao, T.-Y.; Hsu, J.-S. Hva Hsueh Hsueh Pao, 1977, 55, 277; Chem. Abstr. 1978, 89, 22078S.
31. 16. Analysis conducted using two concatenated Techocet OA-3100 colums (total dimensions 4.0mm × 50cm) using 5% methanol in n-butylchloride as the mobile phase.