organic papers Acta Cryst. (2004). E60, o1961±o1963 doi: 10.1107/S1600536804024687 Rosa-Luisa Meza et al.  C 17 H 13 NOSe o1961 Acta Crystallographica Section E Structure Reports Online ISSN 1600-5368 Se-Phenyl 3-(1H-indol-3-yl)selenoacrylate Rosa-Luisa Meza, a Leticia Quintero a and Sylvain Berne Ás b * a Centro de Investigacio Ân de la Facultad de Ciencias Quõ Âmicas, Universidad Auto Ânoma de Puebla, AP 1607, 72001 Puebla, Pue., Mexico, and b Centro de Quõ Âmica, Instituto de Ciencias, Universidad Auto  noma de Puebla, AP 1613, 72000 Puebla, Pue., Mexico Correspondence e-mail: sylvain_bernes@hotmail.com Key indicators Single-crystal X-ray study T = 296 K Mean (C±C) = 0.007 A Ê Disorder in main residue R factor = 0.045 wR factor = 0.108 Data-to-parameter ratio = 13.6 For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e. # 2004 International Union of Crystallography Printed in Great Britain ± all rights reserved The title compound, C 17 H 13 NOSe, has the expected planar indole core and is a rare case of a heavy-atom structure with positional disorder affecting only the heavy atom; the Se atom is disordered over two positions, with equal site-occupation factors (from re®nement). Comment Enamides (N-acyl-1-aminoalkenes) are widely used synthons for the preparation of numerous heterocycles, including some attractive natural products, such as chondriamide A, terpep- tine, aspergillamide A and coscinamide A, among others (Su et al., 2003, and references therein). These indole enamides are currently studied mainly because of their cell-cycle inhibitor activity. During an attempt to synthesize a chondriamide A derivative, we unexpectedly obtained the title compound, (I), as the main product. Interestingly, although our initial goal was not achieved, (I) is of synthetic interest; selenoesters are a useful source of acyl radicals, when treated with trialkyltin hydrides in the presence of a free-radical initiator, generally a Lewis acid. The intramolecular free radical cyclization of free acyl radicals generated from phenyl selenoesters proceeds ef®ciently and, in most cases, with little or no competing reduction or decarbonylation (Studer & Bossart, 2001). Compound (I) is thus a potential entry to ergot alkaloids (Somei et al., 2000), via an Uhle's ketone (Uhle, 1949; Tera- nishi et al., 1995) or a Kornfeld's ketone (Kornfeld et al., 1954, 1956). We report here the crystal structure of (I). The indole core of (I) has the expected planar geometry. Atom C4 is bonded to an ,-unsaturated moiety, lying almost in the indole plane; the dihedral angle between planes C4/C5/ N6/C7/C8/C9/C10/C11/C12 and O1/C1/C2/C3 is 7.0 (3)  .A Received 28 September 2004 Accepted 1 October 2004 Online 9 October 2004