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Synlett 2010(3): 337-354  
DOI: 10.1055/s-0029-1219149
ACCOUNT
© Georg Thieme Verlag Stuttgart ˙ New York

Ethyl Isocyanoacetate as a Useful Glycine Equivalent

Sambasivarao Kotha*, Somnath Halder¹
Department of Chemistry, Indian Institute of Technology - Bombay, Powai, Mumbai 400076, India
Fax: +91(22)25723480; e-Mail: srk@chem.iitb.ac.in;
Further Information

Publication History

Received 5 June 2009
Publication Date:
14 January 2010 (online)

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Abstract

In this account, we describe a useful synthetic approach to construct diverse constrained α,α-dialkylated amino acid derivatives using ethyl isocyanoacetate as a glycine equivalent. Various unusual amino acid derivatives, such as cyclophane-, benzocyclo­butene-, and diene-containing systems, are reported here.

1 Introduction

2 Traditional Methods for the Synthesis of Cyclic α-Amino Acid Derivatives

2.1 Bucherer-Berg Method

2.2 Strecker Method

2.3 Schmidt Rearrangement Method

3 Glycine Equivalents

4 Preparation of Isocyanides

5 Preparation of Ethyl Isocyanoacetate

6 Synthesis of Cyclic Amino Acid Derivatives Using Various Carbon Electrophiles

7 Synthesis of Unusual Cyclophane-Based α-Amino Acid Derivatives

8 Synthesis of Bis-Armed Amino Acid Derivatives

9 Synthesis and Applications of Acyclic and Alicyclic Amino Acid Derivatives

10 Conclusion

Key words

glycine equivalents - amino acids - isocyanides - phase-transfer catalysis - cycloadditions - metathesis - Suzuki coupling

    References

  • 1a Ugi I. Isonitrile Chemistry   Academic; New York: 1971. 
    Google Scholar
  • 1b Dömling A. Ugi I. Angew. Chem. Int. Ed.  2000,  39:  3168 
    Google Scholar
  • 1c Matsumoto K. Suzuki M. Encyclopedia of Reagents for Organic Synthesis   John Wiley and Sons; Chichester: 2001.  p.1 
    Google Scholar
  • 1d Veiderma M. Proc. Estonian Acad. Sci. Chem.  2007,  2:  98; and references cited therein 
    Google Scholar
  • 2a Rothe W. Pharmazie  1950,  5:  190 
    Google Scholar
  • 2b Hagedorn I. Tonjes H. Pharmazie  1956,  11:  409 
    Google Scholar
  • 2c Hagedorn I. Tonjes H. Pharmazie  1957,  12:  567 
    Google Scholar
  • 2d Ugi I. Werner B. Dömling A. Molecules  2003,  8:  53 
    Google Scholar
  • 2e Scheur PJ. Acc. Chem. Res.  1992,  25:  433 
    Google Scholar
  • 2f Garson MJ. Simpson JS. Nat. Prod. Rep.  2004,  21:  164 
    Google Scholar
  • 3a Costa SPG. Maia HLS. Pereira-Lima SMMA. Org. Biomol. Chem.  2003,  1:  1475 
    Google Scholar
  • 3b Schöllkopf U. Hoppe D. Jentsch R. Angew. Chem. Int. Ed. Engl.  1971,  10:  331 
    Google Scholar
  • 3c Schöllkopf U. Hoppe D. Jentsch R. Chem. Ber.  1975,  108:  1580 
    Google Scholar
  • 4a Kotha S. Acc. Chem. Res.  2003,  36:  342 
    Google Scholar
  • 4b Tanaka M. Chem. Pharm. Bull.  2007,  55:  349 
    Google Scholar
  • 4c Park K.-H. Kurth MJ. Tetrahedron  2002,  58:  8629 
    Google Scholar
  • 4d Rilatt I. Caggiano L. Jackson RFW. Synlett  2005,  2701 
    Google Scholar
  • 4e Schiller PW. Weltrowska G. Schmidt R. Nguyen TM.-D. Berezowska I. Lemieux C. Chung NN. Carpenter KA. Wilkes BC. In Drug Discovery Strategies and Methods   Makriyannis A. Biegel D. Marcel Dekker; New York: 2004.  p.147-173  
    Google Scholar
  • 5 Synthesis of Optically Active α-Amino Acids   Williams RM. Pergamon; Oxford: 1989. 
    Google Scholar
  • 6a Giannis A. Kolter T. Angew. Chem. Int. Ed. Engl.  1993,  32:  1244 
    Google Scholar
  • 6b Cativiela C. Diaz-de-Villegas MD. Tetrahedron: Asymmetry  2000,  11:  645 
    Google Scholar
  • 6c Gibson (née Thomas) SE. Guillo N. Tozer MJ. Tetrahedron  1999,  55:  585 
    Google Scholar
  • 7a Avindano C. Trigo GG. In Advances in Heterocyclic Chemistry   Vol. 38:  Academic; New York: 1985.  p.177 
    Google Scholar
  • 7b Trigalo F. Buisson D. Azerad R. Tetrahedron Lett.  1988,  29:  6109 
    Google Scholar
  • 7c Franceschetti L. Garzon-Aburbeh A. Mahmoud MR. Natalini B. Pellicciari R. Tetrahedron Lett.  1993,  34:  3185 
    Google Scholar
  • 7d Fatino G. Fogagnolo M. Guenini R. Marastoni M. Medici A. Pedrini P. Tetrahedron  1994,  53:  12973 
    Google Scholar
  • 7e Ezquerra J. Yruretagoyena B. Avendano C. de la Cuesta E. Gonzalez R. Prieto L. Pedregal C. Espada M. Prowse W. Tetrahedron  1995,  54:  3271 
    Google Scholar
  • 7f Tellier F. Acher F. Brabet I. Pin J.-P. Azerad R. Bioorg. Med. Chem. Lett.  1998,  6:  195 
    Google Scholar
  • 7g Baker SR. Hancox TC. Tetrahedron Lett.  1999,  40:  781 
    Google Scholar
  • 8a Strecker A. Justus Liebigs Ann. Chem.  1850,  75:  27 
    Google Scholar
  • 8b Strecker A. Justus Liebigs Ann. Chem.  1854,  91:  349 
    Google Scholar
  • 8c Kendall EC. McKenzie BF. Org. Synth., Coll. Vol. I  1941,  21 
    Google Scholar
  • 8d Clarke HT. Bean HJ. Org. Synth., Coll. Vol. II  1943,  29 
    Google Scholar
  • 9a George GI. Guan X. Kant J. Tetrahedron Lett.  1988,  29:  403 
    Google Scholar
  • 9b Ridvan L. Abdallah N. Holakovsky R. Tichy M. Zavada J. Tetrahedron: Asymmetry  1996,  7:  231 
    Google Scholar
  • 10 Suginome M. Ito Y. In Science of Synthesis   Vol 19:  Thieme; Stuttgart: 2004.  p.480 
    Google Scholar
  • 11a Elschenbroich G. Salzar A. Organometallchemie   Teubner; Stuttgart: 1993. 
    Google Scholar
  • 11b Kazmaier U. Ackermann S. Synlett  2004,  2576 
    Google Scholar
  • 11c Lim YY. Stein AR. Can. J. Chem.  1971,  49:  2455 
    Google Scholar
  • 12 Ugi I. Fetzer U. Eholzer U. Knupfer H. Offermann K. Angew. Chem., Int. Ed. Engl.  1965,  4:  472 
    CrossrefGoogle Scholar
  • 13a Gautier A. Justus Liebigs Ann. Chem.  1867,  142:  289 
    Google Scholar
  • 13b Gautier A. Justus Liebigs Ann. Chem.  1868,  146:  119 
    Google Scholar
  • 13c Hofmann AW. Justus Liebigs Ann. Chem.  1867,  144:  114 
    Google Scholar
  • 14a Li X. Danishefsky SJ. J. Am. Chem. Soc.  2008,  130:  5446 
    Google Scholar
  • 14b Li X. Yuan Y. Berkowitz WF. Todaro LJ. Danishefsky SJ. J. Am. Chem. Soc.  2008,  130:  13222 
    Google Scholar
  • 14c Li X. Yuan Y. Kan C. Danishefsky SJ. J. Am. Chem. Soc.  2008,  130:  13225 
    Google Scholar
  • 14d Ugi I. Befz W. Fetzer U. Offermann K. Chem. Ber.  1961,  94:  2814 
    Google Scholar
  • 14e Skorna G. Ugi I. Angew. Chem., Int. Ed. Engl.  1977,  16:  259 
    Google Scholar
  • 14f Eckert H. Forster B. Angew. Chem., Int. Ed. Engl.  1987,  26:  894 
    Google Scholar
  • 14g Obrecht R. Herrmann R. Ugi I. Synthesis  1985,  400 
    Google Scholar
  • 15 Porcheddu A. Giacocomelli G. Salaris M. J. Org. Chem.  2005,  70:  2361 
    CrossrefPubMedGoogle Scholar
  • 16a Bossio R. Marcaccini S. Pepino R. Liebigs Ann. Chem.  1991,  1107 
    Google Scholar
  • 16b Bossio R. Marcaccini S. Pepino R. Liebigs Ann. Chem.  1993,  1229 
    Google Scholar
  • 16c Bossio R. Marcaccini S. Pepino R. Liebigs Ann. Chem.  1990,  935 
    Google Scholar
  • 16d Bossio R. Marcaccini S. Pepino R. Torroba T. Synthesis  1993,  783 
    Google Scholar
  • 16e Bossio R. Marcaccini S. Paoli P. Pepino R. Synthesis  1994,  672 
    Google Scholar
  • 16f Paoli P. Papaleo P. Pepino R. Tetrahedron Lett.  1995,  36:  2325 
    Google Scholar
  • 16g Paoli P. Papaleo P. Pepino R. J. Org. Chem.  1996,  61:  2202 
    Google Scholar
  • 16h Bossio R. Marcos CF. Marcaccini S. Pepino R. Tetrahedron Lett.  1997,  38:  2519 
    Google Scholar
  • 16i Bossio R. Marcos CF. Marcaccini S. Pepino R. Synthesis  1997,  1389 
    Google Scholar
  • 16j Bossio R. Marcos CF. Marcaccini S. Pepino R. Heterocycles  1997,  45:  1589 
    Google Scholar
  • 17a Ugi I. Fetzer U. Knupfer H. Offermann K. Angew. Chem., Int. Ed. Engl.  1965,  4:  472 
    Google Scholar
  • 17b Haytman GD. Weinstock LM. Org. Synth., Coll. Vol. VI  1988,  620 
    Google Scholar
  • 18 Zhu J. Wu X. Danishefsky SJ. Tetrahedron Lett.  2009,  50:  577 
    CrossrefPubMedGoogle Scholar
  • 19 Kotha S. Behera M. Khedkar P. Tetrahedron Lett.  2004,  45:  7589 
    CrossrefGoogle Scholar
  • 20a Hruby VJ. Biopolymers  1993,  33:  1073 
    Google Scholar
  • 20b Liskamp RMJ. Recl. Trav. Chim. Pays-Bas  1994,  113:  1 
    Google Scholar
  • 20c Duthaler RO. Tetrahedron  1994,  50:  1539 
    Google Scholar
  • 20d Basak A. Schmidt C. Ismail AA. Seidah NG. Chretien M. Lazure C. Int. J. Pept. Protein Res.  1995,  46:  228 
    Google Scholar
  • 20e Hermkens PHH. Ottenheijm HCJ. van der Werf-Pieters JML. Broekkamp CLE. de Boer T. van Nispen JW. Recl. Trav. Chim. Pays-Bas  1993,  112:  95 
    Google Scholar
  • 20f Adang AEP. Hermkens PHH. Linders JTM. Ottenheijm HCJ. van Staveren CJ. Recl. Trav. Chim. Pays-Bas  1994,  113:  63 
    Google Scholar
  • 21a Balaram P. Curr. Opin. Struct. Biol.  1992,  2:  845 
    Google Scholar
  • 21b Toniolo C. Benedetti E. ISI Atlas of Science: Biochemistry  1988,  225 
    Google Scholar
  • 22a Torrini I. Zecchini GP. Paradisi MP. Lucente G. Gavuzzo E. Mazza F. Pochetti G. Spisani S. Giuliani AL. Int. J. Pept. Protein Res.  1991,  38:  495 
    Google Scholar
  • 22b Hsieh KH. Jorgensen EC. Lee TC. J. Med. Chem.  1979,  22:  1038 
    Google Scholar
  • 22c Nolan PW. Ratcliffe GS. Rees DC. Tetrahedron Lett.  1992,  33:  6879 
    Google Scholar
  • 23a O’Donnell MJ. Boniece JM. Earp SE. Tetrahedron Lett.  1978,  19:  2641 
    Google Scholar
  • 23b Ghosz L. Antoine J.-P. Deffense E. Navarro M. Libert V. O’Donnell MJ. Bruder WA. Tetrahedron Lett.  1982,  23:  4255 
    Google Scholar
  • 23c O’Donnell MJ. Wojciechowski K. Synthesis  1984,  313 
    Google Scholar
  • 24 Kotha S. Kuki A. Tetrahedron Lett.  1992,  33:  1565 
    CrossrefGoogle Scholar
  • 25 Kotha S. Anglos D. Kuki A. Tetrahedron Lett.  1992,  33:  1569 
    CrossrefGoogle Scholar
  • 26 Bhandari A. Jones DG. Schullek JR. Vo K. Schunk CA. Tamanaha LL. Chen D. Yuan Z. Needels MC. Gallop MA. Bioorg. Med. Chem. Lett.  1998,  8:  2303 
    CrossrefPubMedGoogle Scholar
  • 27a Kotha S. Brahmachary E. J. Org. Chem.  2000,  65:  1359 
    Google Scholar
  • 27b Kotha S. Brahmachary E. Bioorg. Med. Chem. Lett.  1997,  7:  2719 
    Google Scholar
  • 27c Lakshminarasimhan D. Rao SN. Pattabhi V. Behera M. Kotha S. Acta Crystallogr., Sect. C  2002,  58:  266 
    Google Scholar
  • 28 Kotha S. Brahmachary E. Kuki A. Lang K. Anglos D. Singaram B. Chrisman W. Tetrahedron Lett.  1997,  38:  9031 
    CrossrefGoogle Scholar
  • 29 Staszewska A. Stefanowicz P. Szewczuk Z. Tetrahedron Lett.  2005,  46:  5525 
    CrossrefGoogle Scholar
  • 30 El-Faham A. El Massry AM. Amer A. Gohar YM. Lett. Pept. Sci.  2002,  9:  49 
    Google Scholar
  • 31 Kotha S. Halder S. Lahiri K. Synthesis  2002,  339 
    Article in Thieme ConnectGoogle Scholar
  • 32a Williams LJ. Jagadish B. Lansdown MG. Carducci MD. Mash EA. Tetrahedron  1999,  55:  14301 
    Google Scholar
  • 32b Williams LJ. Jagadish B. Lyon SR. Kloster RA. Carducci MD. Mash EA. Tetrahedron  1999,  55:  14281 
    Google Scholar
  • 33 Ellis TK. Hochla VM. Soloshonok VA. J. Org. Chem.  2003,  68:  4973 
    CrossrefPubMedGoogle Scholar
  • 34 Lohier J.-F. Wright K. Peggion C. Formaggio F. Toniolo C. Wakselman M. Mazaleyrat J.-P. Tetrahedron  2006,  62:  6203 
    CrossrefGoogle Scholar
  • 35a Mazaleyrat J.-P. Gaucher A. Goubard Y. Savrda J. Wakselman M. Tetrahedron Lett.  1997,  38:  2091 
    Google Scholar
  • 35b Mazaleyrat J.-P. Goubard Y. Azzini M.-V. Wakselman M. Peggion C. Formaggio F. Toniolo C. Eur. J. Org. Chem.  2002,  1232 
    Google Scholar
  • 35c Mazaleyrat J.-P. Goubard Y. Azzini M.-V. Wakselman M. Formaggio CF. Toniolo C. In Peptides 2000   Martinez J. Fehrentz JA. EDK; Paris: 2001.  p.185 
    Google Scholar
  • 36 Kotha S. Brahmachary E. Indian J. Chem., Sect. B: Org. Chem. Incl. Med. Chem.  2001,  40:  1 
    Google Scholar
  • 37 Kumaradhas P. Gupta KR. Kotha S. Brahmachary E. Nirmala KA. Anal. Sci.  2008,  24:  65 
    CrossrefGoogle Scholar
  • 38a

    Kotha, S.; Krishna, N. G.; Misra, S.; Khedkar, P. unpublished results

  • 38b Kotha S. Khedkar P. J. Org. Chem.  2009,  74:  5667 
    Google Scholar
  • 38c Kotha S. Brahmachary E. Lahiri K. Eur. J. Org. Chem.  2005,  4741 
    Google Scholar
  • 39 Kotha S. Behera M. Indian J. Chem., Sect. B: Org. Chem. Incl. Med. Chem.  2004,  43:  922 
    Google Scholar
  • 40a Kotha S. Behera M. Kumar RV. Bioorg. Med. Chem. Lett.  2002,  12:  105 
    Google Scholar
  • 40b Damodharan L. Pattabhi V. Behera M. Kotha S. Acta Crystallogr., Sect. C  2003,  59:  216 
    Google Scholar
  • 40c Damodharan L. Pattabhi V. Behera M. Kotha S. J. Mol. Struct.  2004,  705:  101 
    Google Scholar
  • 40d Kotha S. Behera M. J. Pept. Res.  2004,  64:  72 
    Google Scholar
  • 40e Kotha S. Lahiri K. Kashinath D. Tetrahedron  2002,  58:  9633 
    Google Scholar
  • 40f Kotha S. Lahiri K. Eur. J. Org. Chem.  2007,  1221 
    Google Scholar
  • 41 Mehta G. Kotha S. Tetrahedron  2001,  57:  625 ; and references cited therein
    CrossrefGoogle Scholar
  • 42 Kotha S. Halder S. Sreenivasachary N. ARKIVOC  2002,  (vii):  21 
    Google Scholar
  • 43 Lasa M. Lopez P. Cativiela C. Tetrahedron: Asymmetry  2005,  16:  4022 
    CrossrefGoogle Scholar
  • 44a Kotha S. Halder S. Damodharan L. Pattabhi V. Bioorg. Med. Chem. Lett.  2002,  12:  1113 
    Google Scholar
  • 44b Kotha S. Halder S. ARKIVOC  2005,  (iii):  56 
    Google Scholar
  • 44c Damodharan L. Ibrahim BS. Pattabhi V. Halder S. Kotha S. Acta Crystallogr., Sect. E  2002,  58:  1038 
    Google Scholar
  • 45a Nieto M. Perkins HR. J. Biochem.  1971,  123:  789 
    Google Scholar
  • 45b Belohradský M. Budesínský M. Císarová I. Dekoj V. Holý P. Závada J. Tetrahedron  2003,  59:  7751 
    Google Scholar
  • 45c Ionescu RD. Blom A. Frejd T. Tetrahedron: Asymmetry  2003,  14:  2369 
    Google Scholar
  • 45d Sandhu SS. Hundal MS. Sood G. Dhilon SS. Polyhedron  1989,  8:  1329 
    Google Scholar
  • 46 Kotha S. Shah VR. Halder S. Vinodkumar R. Lahiri K. Amino Acids  2007,  387 
    CrossrefGoogle Scholar
  • 47 Hoppe D. Angew. Chem., Int. Ed. Engl.  1974,  13:  789 
    CrossrefGoogle Scholar
  • 48 Ramalingam K. Kalvin D. Woodard R. J. Labelled Compd. Radiopharm.  1984,  21:  833 
    CrossrefGoogle Scholar
  • 49 Kalvin D. Ramalingam K. Woodard R. Synth. Commun.  1985,  15:  267 
    CrossrefGoogle Scholar
  • 50 Kotha S. Sreenivasachary N. Bioorg. Med. Chem. Lett.  1998,  8:  257 
    CrossrefPubMedGoogle Scholar
  • 51a Casabona D. Cativiela C. Synthesis  2006,  2440 
    Google Scholar
  • 51b Larionov OV. Kozhushkov SI. de Meijere A. Synthesis  2005,  158 
    Google Scholar
  • 51c Brunel JM. Protein Pept. Lett.  2005,  12:  281 
    Google Scholar
  • 52 Casabona D. Jimenez AI. Cativiela C. Tetrahedron  2007,  63:  5056 
    CrossrefPubMedGoogle Scholar
  • 53 Kotha S. Sreenivasachary N. Mohanraja K. Durani S. Bioorg. Med. Chem. Lett.  2001,  11:  1421 
    CrossrefPubMedGoogle Scholar
  • 54 Ohwada T. Kojima D. Kiwada T. Futaki S. Sugiura Y. Yamaguchi K. Nishi Y. Kobayashi Y. Chem. Eur. J.  2004,  10:  617 
    CrossrefPubMedGoogle Scholar
  • 55a Hammer K. Undheim K. Tetrahedron  1997,  53:  2309 
    Google Scholar
  • 55b Hammer K. Undheim K. Tetrahedron  1997,  53:  5925 
    Google Scholar
  • 55c Krikstolaityte S. Hammer K. Undheim K. Tetrahedron Lett.  1998,  39:  7595 
    Google Scholar
  • 55d Hammer K. Undheim K. Tetrahedron: Asymmetry  1998,  9:  2359 
    Google Scholar
  • 56 Tanaka M. Anan K. Demizu Y. Kurihara M. Doi M. Suemune H. J. Am. Chem. Soc.  2005,  127:  11570 
    CrossrefPubMedGoogle Scholar
  • 57 Kotha S. Brahmachary E. Sreenivasachary N. Tetrahedron Lett.  1998,  39:  4095 
    CrossrefGoogle Scholar
  • 58 Kotha S. Sreenivasachary N. Brahmachary E. Tetrahedron  2001,  57:  6261 
    CrossrefGoogle Scholar
  • 59 Butler GB. Ottenbrite RM. Tetrahedron Lett.  1967,  4873 
    CrossrefGoogle Scholar
  • 60a Ando K. Akadegawa N. Takayama H. J. Chem. Soc., Perkin Trans. 1  1993,  2263 
    Google Scholar
  • 60b Ando K. Kankake M. Suzuki T. Takayama H. J. Chem. Soc., Chem. Commun.  1992,  1100 
    Google Scholar
  • 61a Schwesinger R. Chimia  1985,  39:  269 
    Google Scholar
  • 61b Schwesinger R. Nachr. Chem., Tech. Lab.  1990,  38:  1214 
    Google Scholar
  • 61c Schwesinger R. Schlemper H. Angew. Chem. Int. Ed. Engl.  1987,  26:  1167 
    Google Scholar
  • 62 Brahmachary E. Ph.D. Thesis   IIT-Bombay; India: 1999. 
    Google Scholar
  • 63 O’Donnell MJ. Eckrich TM. Tetrahedron Lett.  1978,  19:  4625 
    CrossrefGoogle Scholar
  • 64 Kotha S. Brahmachary E. Tetrahedron Lett.  1997,  38:  3561 
    CrossrefGoogle Scholar
  • 65 Kotha S. Brahmachary E. Bioorg. Med. Chem.  2002,  10:  2291 
    CrossrefPubMedGoogle Scholar
  • 66 Grigg R. Scott R. Stevenson P. J. Chem. Soc., Perkin Trans. 1  1988,  1357 
    CrossrefGoogle Scholar
  • 67a Kotha S. Ghosh AK. Tetrahedron  2004,  60:  10833 
    Google Scholar
  • 67b Bianco A. Da Ros T. Prato M. Toniolo C. J. Pept. Sci.  2001,  7:  208 
    Google Scholar
  • 68 Martin N. Altable M. Filippone S. Martin-Domenech A. Synlett  2007,  3077 
    Article in Thieme ConnectGoogle Scholar
  • 69a Senaiar RS. Teske JA. Young DD. Deiters A.
    J. Org. Chem.  2007,  72:  7801 
    Google Scholar
  • 69b Witulski B. Stengel T. Angew. Chem. Int. Ed.  1999,  38:  2426 
    Google Scholar
  • 70 Mindt TL. Schweinsberg C. Brans L. Hagenbach A. Abram U. Tourwe D. Garcia-Garayoa E. Schibli R. ChemMedChem  2009,  4:  529 
    CrossrefPubMedGoogle Scholar
  • 71a Kotha S. Brahmachary E. J. Organomet. Chem.  2004,  689:  158 
    Google Scholar
  • 71b Seyferth D. White DL. J. Am. Chem. Soc.  1972,  94:  3132 
    Google Scholar
  • 72 Halder S. Ph.D. Thesis   IIT-Bombay; India: 2002. 
    Google Scholar
  • 73 Damodharan L. Mohanraja K. Kotha S. Durani S. Pattabhi V. Biopolymers  2001,  59:  330 
    CrossrefPubMedGoogle Scholar
  • 74a Kotha S. Sreenivasachary N. Brahmachary E. Tetrahedron Lett.  1998,  39:  2805 
    Google Scholar
  • 74b Kotha S. Mesharam M. Tiwari A. Chem. Soc. Rev.  2009,  38:  2065 
    Google Scholar
  • 74c Hammer K. Undheim K. Tetrahedron  1997,  53:  10603 
    Google Scholar
  • 75 Lamberto M. Corbett DF. Kilburn JD. Tetrahedron Lett.  2003,  44:  1347 
    CrossrefGoogle Scholar
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