Synlett 2008(5): 702-706  
DOI: 10.1055/s-2008-1042762
LETTER
© Georg Thieme Verlag Stuttgart · New York

A Short Synthesis of Conformationally Constrained Unnatural Bicyclic Amino Acids Containing a Nitrogen Atom at the Ring Juncture: (9aR)- and (9aS)-Octahydropyrido[1,2-a]pyrazine-(3S)-carboxylic Acids (Opc)

Soon Mog So, Chang-Eun Yeom, Seong Mi Cho, Soo Young Choi, Young Keun Chung, B. Moon Kim*
Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 151-747, Korea
Fax: +82(2)8727505; e-Mail: kimbm@snu.ac.kr;
Further Information

Publication History

Received 15 November 2007
Publication Date:
12 February 2008 (online)

Abstract

A short and efficient route to conformationally constrained amino acid analogues, (9aR)- and (9aS)-octahydropyrido[1,2-a]pyrazine-(3S)-carboxylate (Opc) has been developed. The new bicyclic amino acid derivatives can be stored and utilized as a modular unit for the construction of unnatural oligopeptides using conventional peptide coupling methods.

    References and Notes

  • For a review, see:
  • 1a Goodmann M. Ro S. In Burger’s Medicinal Chemistry and Drug Discovery   Vol. 1:  Wolff ME. John Wiley and Sons; New York: 1995.  p.803-861  
  • 1b Gibson SE. Guillo N. Tozer MJ. Tetrahedron  1999,  55:  585 
  • 1c Hruby VJ. Acc. Chem. Res.  2001,  34:  389 
  • For example, see:
  • 2a Roberts NA. Martin JA. Kinchington D. Broadhurst AV. Craig JC. Duncan IB. Galpin SA. Handa BK. Kay J. Krohn A. Lambert RW. Merrett JH. Mills JS. Parkes KEB. Redshaw S. Ritchie AJ. Taylor DL. Thomas GJ. Machin PJ. Science  1990,  248:  358 
  • 2b Kalish VJ. Tetlock JH. Davies JF. Kaldor SW. Dressman BA. Reich S. Pino M. Nyugen D. Appelt K. Musick L. Wu B. Bioorg. Med. Chem. Lett.  1995,  5:  727 
  • 2c Ghosh AK. Hussain KA. Fidanze S. J. Org. Chem.  1997,  62:  6080 
  • For example, see:
  • 3a Hunt JT. Lee VG. Leftheris K. Seizinger B. Carboni J. Mabus J. Ricca C. Yan N. Manne V. J. Med. Chem.  1996,  39:  353 
  • 3b Georg GI. Harriman GB. Ali SM. Datta A. Hepperle M. Himes RH. Bioorg. Med. Chem. Lett.  1997,  5:  115 
  • For example, see:
  • 4a Bigge CF. Wu J. Malone TC. Taylor CP. Vartanian MG. Bioorg. Med. Chem. Lett.  1993,  3:  39 
  • 4b Ho B. Crider AM. Stables JP. Eur.
    J. Med. Chem.  2001,  205 
  • For example, see:
  • 5a Thurieau C. Félétou M. Hennig P. Raimbaud E. Canet E. Fauchère J. J. Med. Chem.  1996,  39:  2095 
  • 5b Mavunkel BJ. Lu Z. Goehring RR. Lu S. Chakravarty S. Perumattam J. Novotny EA. Connolly M. Valentine H. Kyle DJ. J. Med. Chem.  1996,  39:  3169 
  • 6 For example, see: Shuman RT. Rothenberger RB. Campbell CS. Smith GF. Gifford-Moore DS. Gesellchen PD. J. Med. Chem.  1993,  36:  314 
  • For example, see:
  • 7a Klutchko S. Blankley CJ. Fleming RW. Hinkley JM. Werner AE. Nordin I. Holmes A. Hoefle ML. Cohen DM. J. Med. Chem.  1986,  29:  1953 
  • 7b Rosenkranz RP. Hayashi CM. Lakatos I. McClelland DL. Proc. West. Pharmacol. Soc.  1989,  32:  221 
  • 8 For example, see: Steinbaugh BA. Hamilton HW. Patt WC. Rapundalo ST. Batley BA. Lunney EA. Ryan MJ. Hicks GW. Bioorg. Med. Chem. Lett.  1994,  4:  2029 
  • 9 For example, see: Klutchko S. Hamby JM. Hodges JC. Bioorg. Med. Chem. Lett.  1994,  4:  57 
  • 10a Katritzky AR. Rachwal S. Rachwal B. Tetrahedron  1996,  52:  15031 
  • 10b Barbier D. Marazano C. Riche C. Das BC. Potier P. J. Org. Chem.  1998,  63:  1767 
  • 10c Mash EA. Williams LJ. Pfeiffer SS. Tetrahedron Lett.  1997,  38:  6977 
  • 10d Kametani T. The Total Synthesis of Isoquinoline Alkaloids, In The Total Synthesis of Natural Products   Vol. 3:  ApSimon J. John Wiley; New York: 1977.  p.1-272  
  • 11a Kim BM. Bae SJ. So SM. Yoo HT. Chang SK. Lee JH. Kang JS. Org. Lett.  2001,  3:  2349 
  • 11b Kim BM. Vacca JP. Guare JP. Hanifin CM. Michelson SR. Darke PL. Zugay JA. Emini EA. Schleif W. Lin JH. Chen I.-W. Vastag K. Ostovic D. Anderson PS. Huff JR. Bioorg. Med. Chem. Lett.  1994,  4:  2273 
  • 11c Kim BM. G uare JP. Vacca JP. Michelson SR. Darke PL. Zugay JA. Emini EA. Schleif W. Lin JH. Chen I.-W. Vastag K. Anderson PS. Huff JR. Bioorg. Med. Chem. Lett.  1995,  5:  185 
  • 12a Kim BM, Graham SL, Shaw AW, de Solms J, and Ciccarone T. inventors; US  5,817,678. 
  • 12b Kim BM, Shaw AW, Graham SL, de Solms JS, and Ciccarone TM. inventors; EP  0862435. 
  • 13a Baldwin JE. Spivey AC. Schofield CJ. Tetrahedron: Asymmetry  1990,  1:  881 
  • 13b Ok D. Fisher MH. Wyvratt MJ. Meinke PT. Tetrahedron Lett.  1999,  40:  3831 
  • 13c Cohen SB. Halcomb RL. Org. Lett.  2001,  3:  405 
  • 13d Atfani M. Wei L. Lubell WD. Org. Lett.  2001,  3:  2965 
  • 13e Cohen SB. Halcomb RL. J. Am. Chem. Soc.  2002,  124:  2534 
  • 13f Nicolaou KC. Huang X. Snyder SA. Rao PB. Bella M. Reddy MV. Angew. Chem. Int. Ed.  2002,  41:  834 
  • 13g Posakony JJ. Grierson JR. Tewson TJ. J. Org. Chem.  2002,  67:  5164 
  • 13h Pound MK. Davies DL. Pilkington MPV. Sousa MM. Wallis JD. Tetrahedron Lett.  2002,  43:  1915 
  • 14a Kim BM. So SM. Tetrahedron Lett.  1998,  39:  5381 
  • 14b Kim BM. So SM. Tetrahedron Lett.  1999,  40:  7687 
  • 14c Kim BM. Bae SJ. So SM. Yoo HT. Chang SK. Lee JH. Kang JS. Org. Lett.  2001,  3:  2349 
  • 14d Kim BM. So SM. Choi HJ. Org. Lett.  2002,  4:  949 
  • 15a Baldwin JE. Adlington RM. Mellor LC. Tetrahedron  1994,  50:  5049 
  • 15b Augilera B. Mayoralas AF. Jaramillo C. Tetrahedron  1997,  53:  5863 
  • 15c Wel L. Lubell WD. Org. Lett.  2000,  2:  2595 
  • 16 Rodwell VW. Methods in Enzymology   Part B, Vol. 17:  Academic Press; New York: 1971.  p.174 
  • 17 Henry JR. Marcin LR. McIntosh C. Scola PM. Harris GD. Weinreb SM. Tetrahedron Lett.  1989,  30:  5709 
  • 18a Pederson CJ. J. Am. Chem. Soc.  1967,  89:  7017 
  • 18b Alexander V. Chem. Rev.  1995,  95:  273 
  • 19a Sharpless KB. Kim BM. Tetrahedron Lett.  1989,  30:  655 
  • 19b Okada M. Tomioka K. Tetrahedron Lett.  1994,  35:  4585 
20

CCDC #660993.

21

Characterization Data for Compound 16 [α]D 27 -15.0 (c 1.1, CHCl3). 1H NMR (300 MHz, CDCl3):
δ = 0.03 (s, 6 H), 0.88 (s, 9 H), 1.28 (t, 3 H), 1.32-1.70 (m, 6 H), 2.23-2.45 (m, 1 H), 2.50-2.57 (m, 1 H), 2.64-2.76 (m, 3 H), 2.97-3.05 (m, 1 H), 3.38-3.51 (m, 2 H), 3.94 (ABq, J = 13.3 Hz, 2 H), 3.96-3.88 (m, 1 H), 4.26-4.32 (m, 2 H), 7.21-7.32 (m, 5 H). 13C NMR (75 MHz, CDCl3): δ = -5.47, 14.28, 18.21, 22.16, 25.39, 25.84, 28.20, 51.06, 52.14, 56.96, 59.58, 60.34, 62.17, 63.70, 126.86, 128.16, 128.22, 139.85, 174.46. HRMS (CI): m/z calcd for C23H41N2O3Si
[M + H]+: 421.2886; found: 421.2884.

22

Characterization Data for Compound 17 [α]D 28 -4.1 (c 1.1, CHCl3). 1H NMR (300 MHz, CDCl3): δ = 1.29 (t, 3 H), 1.37-1.71 (m, 6 H), 2.27-2.45 (m, 2 H), 2.57-2.64 (m, 1 H), 2.82-2.91 (m, 1 H), 2.98-3.05 (m, 1 H), 3.22 (br s, 2 H), 3.35-3.42 (m, 2 H), 3.67-3.76 (m, 1 H), 3.75 (ABq, J = 12.9, 2 H), 4.13-4.24 (m, 2 H), 7.22-7.32 (m, 5 H). 13C NMR (75 MHz, CDCl3): δ = 14.25, 23.71, 23.86, 27.05, 52.47, 52.74, 54.38, 59.89, 60.92, 61.95, 63.07, 127.20, 128.35, 128.42, 139.03, 174.90. HRMS (CI): m/z calcd for C18H29N2O3 [M + H]+: 321.2178; found: 321.2176.

23

Characterization Data for Compound 19 [α]D 27 -10.5 (c 1.0, CHCl3). 1H NMR (300 MHz, CDCl3):
δ = 1.12-1.29 (m, 2 H), 1.27 (t, 3 H), 1.34-1.41 (m, 1 H), 1.56-1.59 (m, 2 H), 1.65-1.68 (m, 1 H), 1.87-1.96 (m, 2 H), 2.38-2.48 (m, 2 H), 2.70-2.74 (m, 1 H), 2.90-2.97 (m, 1 H), 3.04-3.08 (m, 1 H), 3.40 (s, 1 H), 3.90 (ABq, J = 13.7, 2 H), 4.14-4.24 (m, 2 H), 7.20-7.31 (m, 5 H). 13C NMR (75 MHz, CDCl3): δ = 14.78, 24.37, 25.96, 29.91, 53.41, 56.15, 58.27, 59.35, 60.25, 60.62, 61.85, 127.30, 128.65, 129.03, 139.75, 172.83. HRMS (CI): m/z calcd for C18H27N2O2 [M + H]+: 303.2072; found: 303.2073.

24

Characterization Data for Compound 22 [α]D 11 -31.3 (c 1.00, CHCl3).1H NMR (300 MHz, CDCl3):
δ = 1.11-1.96 (m, 17 H), 2.24-2.31 (m, 1 H), 2.70-2.88 (m, 2 H), 3.17-3.24 (m, 1 H), 3.62 (d, J = 3.2 Hz, 0.25 H), 3.66 (d, J = 3.2 Hz, 0.25 H), 3.74-3.80 (m, 3.5 H), 4.53 (d, J = 4 Hz, 0.5 H), 4.70 (d, J = 4 Hz, 0.5 H). 13C NMR (75 MHz, CDCl3): δ = 24.02, 24.07, 25.67, 28.64, 28.73, 29.54, 29.56, 46.87, 47.84, 52.58, 54.38, 55.65, 55.81, 55.93, 56.17, 60.70, 60.72, 80.55, 80.60, 155.54, 155.96, 171.68, 171.98. HRMS-FAB: m/z calcd for C15H27N2O4 [M + H]+: 299.1971; found: 299.1970.

25

Characterization Data for Compound 23 [α]D 11 +23.9 (c 1.00, CHCl3). 1H NMR (300 MHz, CDCl3): δ = 1.12-1.28 (m, 2 H), 1.51-1.61 (m, 3 H), 1.72-1.98 (m, 3 H), 2.03 (s, 0.7 H), 2.14 (s, 2.3 H), 2.24 (dd, 0.75 H), 2.33 (dd, 0.25 H), 2.49-2.61 (m, 0.25 H), 2.77-2.80 (m, 0.75 H), 3.09-3.18 (m, 0.9 H), 3.24-3.38 (m, 1.2 H), 3.43-3.54 (m, 0.9 H), 3.75 (s, 2.3 H), 3.79 (s, 0.7 H), 4.22-4.23 (m, 0.08 H), 4.27-4.28 (m, 0.08 H), 4.34-4.37 (m, 0.14 H), 5.17-5.19 (m, 0.7 H). 13C NMR (75 MHz, CDCl3): δ = 21.52, 21.81, 23.98, 25.58, 25.67, 29.55, 29.62, 45.07, 49.88, 52.51, 52.76, 53.12, 55.72, 55.82, 56.04, 56.43, 57.57, 60.63, 60.98, 170.79, 171.01, 171.22. HRMS-FAB: m/z calcd for C12H21N2O3 [M + H]+: 241.1552; found: 241.1558.

26

Characterization Data for Compound 24 [α]D 11 -59.2 (c 1.00, CHCl3). 1H NMR (300 MHz, CDCl3):
δ = 1.03-1.31 (m, 2 H), 1.41-2.01 (m, 6 H), 2.12 (s, 1.2 H), 2.23 (m, 1.8 H), 2.34-2.52 (m, 2 H), 2.78-2.86 (m, 1 H), 3.03-3.15 (m, 1 H), 3.29-3.33 (m, 0.4 H), 3.44-3.48 (m, 0.4 H), 3.71-3.78 (m, 0.2 H), 4.32-4.55 (m, 2.6 H), 5.18-5.20 (m, 0.4 H), 7.05 (s, 0.4 H), 7.26-7.69 (m, 5 H), 8.46 (m, 0.6 H). 13C NMR (75 MHz, CDCl3): δ = 21.89, 21.96, 23.81, 23.94, 25.62, 25.89, 29.62, 29.74, 43.78, 43.83, 44.07, 50.02, 52.95, 55.26, 55.52, 55.735, 55.89, 57.70, 60.75, 61.26, 126.29, 127.75, 127.88, 127.91, 128.22, 129.050, 129.14, 138.39, 138.70, 169.76, 170.05, 170.51, 170.91. HRMS-FAB: m/z calcd for C18H26N3O2 [M + H]+: 316.2025; found: 316.2026.