461432-23-5

1103738-19-7

1103738-30-2

Using 4-(2-chloro-5-bromobenzyl)phenyl ethyl ether (Compound C-1, 10 g, 30.7 mmol) and ((3AS,5R,6S,6AS)-6-hydroxy-2,2-dimethyltetrahydrofuro[2,3-d][1,3]dioxol-5-yl)(morpholino)methanone (Compound B, 9.6 g, 35.3 mmol, 1.15 equivalent) as raw material, the general procedure for the synthesis of (4-chloro-3-(4-ethoxybenzyl)phenyl)((3AS,5R,6S,6AS)-6-hydroxy-2,2-dimethyltetrahydrofuro[2,3-d][1,3]dioxol-5-yl)methanone (Compound D-1) was carried out as follows: dissolve Compound C-1 (10 g, 30.7 mmol) in 70 mL of tetrahydrofuran in a 250 mL three-necked flask and stirred until completely dissolved. The solution was cooled to -70 to -80 °C, n-butyllithium solution (2.5 M THF solution, 14.1 mL, 1.15 eq.) was slowly added dropwise and stirred continuously for 1 hour at this temperature. Subsequently, a tetrahydrofuran solution of compound B (9.6 g of B dissolved in 30 mL of tetrahydrofuran) was slowly added dropwise to the reaction mixture. After the dropwise addition was completed, the reaction mixture was continued to be stirred at -70 to -80 °C for 2 hours. After that, the reaction solution was slowly warmed up to -10 to 0 °C and diluted with saturated aqueous NH4Cl solution (20 mL). The reaction mixture was extracted twice with ethyl acetate (100 mL x 2), the organic phases were combined and washed with brine (100 mL). The organic layer was concentrated to dryness under reduced pressure at 40 to 50 °C. The resulting solid was recrystallized by ethyl acetate and hexane to give 11.5 g of compound D-1 in 86.3% yield.