d-Hydroxy-a,b-unsaturated sugar aldehydes (Perlin aldehydes) undergo smooth coupling with b-enamino ketones and benamino esters generated in situ from arylamines and 1,3-dicarbonyl compounds in the presence of 10 mol% InCl 3 in acetonitrile at 80°C, to produce oxa-aza-bicycles in good yields with high selectivity.The multi-component, one-pot synthetic approach has received considerable attention because of its wide range of applications in pharmaceutical chemistry for the production of diversified structural scaffolds and combinatorial libraries for drug discovery. 1 2,3-Dideoxy-a,b-unsaturated sugar aldehydes, commonly known as Perlin aldehydes, 2 constitute an increasingly important class of carbohydrate derivatives that have been used as precursors for the synthesis of biologically active molecules during the last three decades. [3][4][5] Recently, we have also demonstrated the use of Perlin aldehyde in the synthesis of some biologically interesting heterocycles, such as oxaazabicyles, trans-dihydropyrans and 1,5-benzodiazepines. 6,7 However, there have been no reports on threecomponent coupling of Perlin aldehyde, arylamines and 1,3-diketones.In a continuation of our work on the use of sugars for the synthesis of a novel class of heterocycles, 8,9 we herein report a three component coupling (3CC) of Perlin aldehyde, arylamines and 1,3-dicarbonyl compounds. The 3CC reaction was performed using 10 mol% indium(III) chloride in acetonitrile. We initially studied a threecomponent coupling of Perlin aldehyde, aniline and acetyl acetone using 10 mol% indium(III) chloride and found that the reaction proceeded smoothly in acetonitrile at 80°C to furnish the corresponding bicyclic adduct 4a in 85% yield with high selectivity (Scheme 1).The structure of 4a was established by various NMR experiments. The location of the methylene group in the bridge of a bicyclononene-like structure was confirmed by the observation of small couplings with the bridgehead protons H1 and H3 (J H1-H2(pro-S) = 3.0 Hz, J H1-H2(pro-R) = 2.2 Hz, J H2(pro-S)-H3 = 3.0 Hz, and J H2(pro-S)-H3 = 4.3 Hz, Figure 1). The two six-membered rings of the bicyclononene moiety differ in their conformations: for the pyranose ring, the coupling constant (J H4-H5 = 10.3 Hz) and the H2 (pro-S) /H4 NOESY cross peak, support the 4 C 1 chair form. The H5/H ortho and H1/H ortho NOE correlations further confirm that the N-Ph group is on same side as the ring oxygen, whereas the location of methyl group adjacent to ring nitrogen was confirmed by an observed NOE between C11 and H ortho . Additionally, HMBC correlations (H4/C13, H3/C12 and H1/C12) were in complete agreement with the proposed structure.