Water → HCID 57771620, compound

Participants

Reaction Steps

To a solution of the crude (2R,5R)-2-(tert-butyldiphenylsilanyloxy)-6-hydroxy-spiro[4.5]decane-7-carboxylic acid methyl ester (1.76 g) obtained in Step 5 in pyridine (5 mL) was added methanesulfonyl chloride (0.25 mL) under ice-cooling, followed by stirring the mixture at room temperature for 15 hours. Then, to the reaction mixture was added water, followed by extraction with ethyl acetate. The organic layer was washed with saturated brine, dried and concentrated. The residue was dissolved in tetrahydrofuran (10 mL). To this solution was added 1,8-diazabicyclo[5.4.0]undec-7-ene (0.88 mL), followed by stirring the mixture at 70° C. for 3.5 hours. After cooling down to room temperature and adding water, the reaction mixture was extracted with ethyl acetate. The organic layer was washed successively with 1N aqueous hydrochloric acid solution and saturated brine, dried and concentrated. The residue was purified by column chromatography on silica gel (ethyl acetate:hexane (volume ratio)=1:30 to 1:25) to give (2R,5R)-2-(tert-butyldiphenylsilanyloxy)-spiro[4.5]dec-6-en e-7-carboxylic acid methyl ester (0.615 g).

Provenance & Evidence