1240497-07-7

82911-79-3

GENERAL PROCEDURE: METHOD A-USE OF PLANETARY BALL MILL: Triphenylmethylated compounds (1 mmol; typically 563 mg, 4) and In(OTf)3 (141 mg, 0.25 mmol) were mixed in a 50 mL stainless steel (SS) jar with ten 10-mm diameter SS balls. The reaction was carried out in a planetary ball mill (PM-100) at 550 rpm for 3.5 h (the progress of the reaction was monitored by TLC and the unfolding agent was EtOAc:Hex, 1:1). Upon completion of the reaction, EtOAc was added to the mixture and the solution was transferred to a dispensing funnel (50 ml × 3). The organic phase was washed sequentially with 10% Na2CO3 aqueous solution (50 ml × 2) and water (50 ml), dried with Na2SO4 and concentrated under reduced pressure to obtain the crude de-O-tritylated product. The crude product was purified by fast chromatography to remove the by-product TrOH to give the pure product (yield: 305 mg, 95.2%, 5 from 4). The pure product was crystallized from ether-n-Hex to give an analytically pure product. The spectral data of the product was in agreement with the expected structure and literature values. Method B-Use of a Vibratory Ball Mill: the triphenylmethylated compound (1 mmol; typically 563 mg, 4) and In(OTf)3 (141 mg, 0.25 mmol) were mixed in a 10 mL stainless steel (SS) jar to which 20 SS balls of 3 mm diameter were added. The reaction was carried out in a vibrating ball mill (MM-400) at 30 Hz for 15 min (the progress of the reaction was monitored by TLC and the unfolding agent was EtOAc/Hex, 1:1). The post-treatment and isolation steps of the product were the same as in Method A. The yield was 308 mg, 96.2%, from 4 to 5.