Table . Optimization of the reaction conditions. Entry Modification from standard conditions Yield (%) 1 None 53 In addition to lactones, we were interested to apply the same reaction conditions on homoallylic cesium oxamates to obtain alkynylated -lactams. To our delight, a simple primary tosylprotected amide provided lactam 5k in 71% yield. The structure of 5k was confirmed by X-Ray crystallography. Also, a cishexenamine derivative cyclized successfully to give 5o in 63% yield and 2:1 dr. Despite several attempts, tertiary homoallylic cesium oxamates only provided the product resulting from alkynylation of the aminocarbonyl radical prior to cyclization. We speculate that the 5-exo-trig cyclization is not occurring due to a non-favorable conformation of the aminocarbonyl radical. Nevertheless, spirolactam 5p with a different connectivity can still Modifications: 44 W LEDs, 18 h. be obtained in 76% yield and 6:1 dr starting from a cyclohexenylethylamine oxamate as radical precursor. Finally, the lactamization-alkynylation reaction was performed using a Celecoxib derivative to afford lactam 5q in 48% yield, demonstrating that more complex functionalized sulfonimides were tolerated in the reaction. The scope of the Ar-EBX reagents was then explored on both lactonization and lactamization reactions, using either cesium oxalate 2a or cesium oxamate 2n (Scheme 3). pTolEBX (3b) provided compounds 5r and 5s in 88% and 61% yield, respectively. Halogenated Ar-EBX reagents 3c and 3d were tolerated under the reaction conditions: the fluorinated compound 5t, was isolated in 61% yield; while brominated EBX reagent 3d provided cyclized products 5u and 5v in 84% and 72% yield, respectively. Finally, aryl alkynes containing electron-withdrawing groups such as trifluoromethyl (5w and 5x) and methyl ester (5y and 5z) were obtained in 68%, 44%, 25% and 45% yield, respectively. In order to demonstrate the synthetic utility of the obtained alkynylated spirolactones, post functionalization reactions were carried out from 5a (Scheme 4). First, we envisaged to introduce a different synthetic handle than the alkyne. Therefore, spirolactone 5a was subjected to a one-pot Ru-catalyzed 1,2diketone formation -Baeyer Villiger oxidation procedure, giving carboxylic acid derivative 6 in 73% yield. Second, the lactone was opened reductively by treatment with LiAlH4 leading to 1,4diol 7 having a pendent alkynyl group in 90% yield. Finally, the same reaction conditions were applied to lactone 5i, which had been obtained as a single diastereoisomer, to provide diol 8 in 56% yield. This sequence therefore allowed to install three contiguous stereocenters with high relative stereocontrol.