Synthesis, Table of Contents PAPER © Georg Thieme Verlag Stuttgart · New York Stereoselective Synthesis of 3,4-trans-Disubstituted γ-Lactams by Cerium(IV) Ammonium Nitrate Mediated Radical Cyclization of Cinnamamides Vijay Nair*, Kishor Mohanan, Tachapully D. Suja, Akkattu T. BijuOrganic Chemistry Section, Regional Research Laboratory (CSIR), Trivandrum 695019, IndiaFax: +91(471)2491712; e-Mail: vijaynair_2001@yahoo.com; Recommend Article Abstract Buy Article All articles of this category Abstract A facile synthesis of 3,4-trans-disubstituted γ-lactams was developed, consisting of the radical cyclization of cinnamamides mediated by cerium(IV) ammonium nitrate. The single-electron-transfer (SET) reaction of the methoxystyrenyl moiety mediated by cerium(IV) ammonium nitrate gives rise to a cation radical, whose cyclization followed by reaction with oxygen and methanol generates 3,4-trans-disubstituted γ-lactams. Key words cerium(IV) ammonium nitrate - intramolecular cyclization - cinnamamides - single electron transfer - γ-lactams Full Text References References 1a Imamoto T. Lanthanide Reagents in Organic Synthesis Academic Press; London: 1994. 1b Hwu JR. Curr. Sci. 2001, 81: 1043 1c Ho T.-L. Paquette LA. Encyclopedia of Reagents for Organic Synthesis Wiley; Chichester: 1995. p.1027 2a Nair V. Mathew J. Radhakrishnan KV. J. Chem. Soc., Perkin Trans. 1 1996, 1487 2b Nair V. Mathew J. Prabhakaran J. Chem. Soc. Rev. 1997, 127 2c Nair V. Treesa PM. Maliakal D. Rath NP. Tetrahedron 2001, 57: 7705 3 Nair V. Balagopal L. Rajan R. Mathew J. Acc. Chem. Res. 2004, 37: 21 4 Nair V. Panicker SB. Nair LG. George TG. Augustine A. Synlett 2003, 156 5a Molander GA. Chem. Rev. 1992, 92: 29 5b Narasaka K. Okauchi T. Tanaka K. Murakami M. Chem. Lett. 1992, 2099 5c Narasaka K. Arai N. Okauchi T. Bull. Chem. Soc. Jpn. 1993, 66: 2995 5d Linker T. Sommermann T. Kahlenberg F. J. Am. Chem. Soc. 1997, 119: 9377 6a Takemoto Y. Ibuka T. Tetrahedron Lett. 1998, 39: 7545 6b Snider BB. Kwon T. J. Org. Chem. 1990, 55: 4786 6c Durand A.-C. Dumez E. Rodriguez J. Dulcere J.-P. Chem. Commun. 1999, 2437 6d Baciocchi E. Paolobelli AB. Ruzziconi R. Tetrahedron 1992, 48: 4617 6e Wang L. Seiders JR. Floreancig PE. J. Am. Chem. Soc. 2004, 126: 12596 7a Nair V. Balagopal L. Sheeba V. Panicker SB. Rath NP. Chem. Commun. 2001, 1682 7b Nair V. Mohanan K. Suja TD. Suresh E. Tetrahedron Lett. 2006, 47: 2803 8a Nair V. Balagopal L. Rajan R. Deepthi A. Mohanan K. Rath NP. Tetrahedron Lett. 2004, 45: 2413 8b Nair V. Mohanan K. Suja TD. Suresh E. Tetrahedron Lett. 2006, 47: 705 9a Tchissambou L. Benechie M. Khuong-Huu F. Tetrahedron 1982, 38: 2687 9b Nilsson BM. Ringdahl B. Hacksell U. J. Med. Chem. 1990, 33: 580 9c Bergman R. Gericke R. J. Med. Chem. 1990, 33: 492 9d Garvey DS. May PD. Nadzan AM. J. Org. Chem. 1990, 55: 936 10 The difference between the coupling constants for the benzylic protons in 2a (4.2 Hz) and 2a′ (2.4 Hz) indicates that the isomeric pair 2a and 2a′ differs only in the relative stereochemistry of the methoxy group at the benzylic position.
