to this solution a suspension of aibn 5 6 g 34 00 mmol in toluene 100 ml was added in one portion and heating was continued at reflux temperature for 10 minutes the progress of the reaction was monitored by a tlc with dimensions of 2 5 u00d7 7 5 cm was used to elute reaction mixture in 25 ethyl acetate and hexanes to confirm complete consumption of starting material a longer tlc helped in resolving the spot closer to the rf value of starting material at this stage the reaction was complete and the reaction mixture was cooled to ambient temperature this reaction mixture was concentrated in vacuo to remove toluene to half the original volume and then loaded directly onto the silica gel packed column for purification specifically a filter type column of diameter 11 5 cm and 18 cm length was packed with silica gel 579 7 g was used for purification using ethyl acetate and hexanes the polarity of the solvent was increased from 0 to 9 a smaller filter type column of diameter 9 5 cm and 15 cm length packed with silica gel 396 2 g was used for purifying impure fractions using the above solvents and polarity the pure fractions yielded 8 9 g lot rd ut 1137 175 i with 95 5 purity by uplc and impure fractions were purified again by a second column chromatography to yield 7 03 g lot rd ut 1137 175 ii with 96 26 purity by uplc the total isolated yield of allyl acetoxycyclopentabenzofuran 4 was 15 9 g 65 5 the compound was characterized by 1 h nmr a 1000 ml single necked round bottom flask fitted with a condenser was charged with a.