General information. 1 H and 13 C NMR spectra were recorded on a Bruker Spectrospin Avance DPX400 spectrometer at 400 and 100 MHz, respectively. Chemical shifts are given in parts per million (ppm) relative to tetramethylsilane (TMS). Coupling constants (J) are given in hertz (Hz), and spin multiplicities as follows: s (singlet), d (doublet), t (triplet), q (quartet), m (multiplet). DEPT 13 C NMR information is depicted in parentheses as C, CH, CH 2 and CH 3 . IR data were obtained on a Bruker Alpha spectrophotometer by using attenuated total reflection (ATR). Band positions are recorded in reciprocal centimeters (cm -1 ). Highresolution mass spectra (HRMS) were obtained on a Agilent 6224 TOF LC/MS spectrometer by using electrospray ionization (ESI) with Micro-Tof; m/z values are reported (for each measurement, the mass scale was recalibrated with sodium formate clusters, and samples were dissolved and measured in CH 3 OH or CH 3 CN. Melting points were determined with a Stuart SMP50 apparatus. Flash chromatography was performed using thick-walled glass columns and 'flash grade' silica gel (230-400 mesh). TLC was accomplished by using commercially prepared 0.25 mm silica gel and visualization was effected with a shortwavelength UV lamp (254 nm). The relative proportions of solvents in chromatography solvent mixtures refer to the volume/volume ratio. All commercially available reagents were used directly without purification unless otherwise stated. All solvents used in reactions and chromatography were distilled and/or dried properly for purity. The inert atmosphere was created by a slight positive pressure (ca. 0.1 psi) of argon. All glassware was oven-dried prior to use.The necessary N-propargylic β-enaminones 1, arylated N-propargylic β-enaminones 2 and spiro-2H-pyrroles 5 were synthesized according to Table 1, Table 2 and Table 3, respectively, as shown below. 1,2

A one-pot two-step protocol for the synthesis of 2-acetyl-1H-pyrroles from N-propargylic β-enaminones was described. When treated with zinc chloride in refluxing chloroform, N-propargylic β-enaminones produced in situ 2-methylene-2,3-dihydro-1,4-oxazepines, which, upon further refluxing in methanol with zinc chloride, afforded 2-acetyl-1H-pyrroles. The process was found to be general for a wide variety of N-propargylic β-enaminones and yielded a diverse range of 2-acetyl-1H-pyrroles in good to high yields with large substrate scope and good functional group tolerance. This operationally easy method may provide a rapid access to functionalized 2-acetyl-1H-pyrroles of pharmacological interest.