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With Dess-Martin periodane In dichloromethane at 20℃; for 3h;
19
To a solution of compound 14-3 (322 mg, 1 mmol) in 20 mL dichloromethane was added Dess-Martin Periodinane (636 mg, 1.5 mmol). The reaction mixture was stirred at room temperature for 3 hours. The reaction was quenched with a solution of sodium thiosulfate (1.4 g, 8.85 mmol) in 15 mL of saturated sodium bicarbonate. The mixture was separated. The organic layer was washed with saturated sodium bicarbonate, brine, dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography using SiliaSep Cartridges (40g), eluting with 0-100%> ethyl acetate/hexanes to give 170mg (53%) of compound 19-5.
53%
With Dess-Martin periodane In dichloromethane at 20℃; for 3h;
19 Compound 19-5
To a solution of compound 14-3 (322 mg, 1 mmol) in 20 mL10 dichloromethane was added Dess-Martin Periodinane (636 mg, 1.5 mmol). The reaction mixture wasstirred at room temperature for 3 hours. The reaction was quenched with a solution of sodiumthiosulfate (1.4 g, 8.85 mmol) in 15 mL of saturated sodium bicarbonate. The mixture wasseparated. The organic layer was washed with saturated sodium bicarbonate, brine, dried oversodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column15 chromatography using SiliaSep Cartridges ( 40g), eluting with 0-100% ethyl acetate/hexanes to give170mg (53%) of compound 19-5.
With Dess-Martin periodane In dichloromethane at 20℃; for 3h;
19 Compound 19-5
Compound 19-5: To a solution of compound 14-3 (322 mg, 1 mmol) in 20 mLdichloromethane was added Dess-Martin Periodinane (636 mg, 1.5 mmol). The reaction10 mixture was stirred at room temperature for 3 hours. The reaction was quenched with asolution of sodiwn thiosulfate (1.4 g, 8.85 mmol) in 15 mL of saturated sodium bicarbonate.The mixture was separated. The organic layer was washed with saturated sodium bicarbonate,brine, dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purifiedby flash column chromatography using SiliaSep Cartridges ( 40g), eluting with 0-100% ethyl15 acetate/hexanes to give 170mg (53%) of compound 19-5.
With sodium cyanoborohydride; acetic acid In N,N-dimethyl-formamide at 20℃; for 2h;
19 Compound 19-6
Compound 19-6: To a solution of monomethyldolastatin hydrochloride 1.0 g( 1.24 mmol) in 20 mL of DMF was added 1.19 g (3. 72 mmol) of compound 17 followed by1.4 mL (24.8 mmol) of acetic acid and 156 mg (2.48 mmol) of sodium cyanoborohydride.The resulting mixture was stirred at room temperature for 2 hours. The solvent was removed20 in vacuo. The residue was adjusted to pH 8 by sodium bicarbonate and extracted with DCM,washed with brine, dried over sodium sulfate, filtered and concentrated in vacuo. The residuewas purified by flash column chromatography using SiliaSep Cartridges ( 40g), eluting with0-5% methanol/DCM to give 680mg (51%) of compound 19-6. MS (ESI) m/z 538 [M+2H],1075 [M+H].
With sodium cyanoborohydride; acetic acid In N,N-dimethyl-formamide at 20℃; for 2h;
19 Compound 19-6
To a solution of monomethyldolastatin hydrochloride 1.0 g (1.24mmol) in 20 mL of DMF was added 1.19 g (3.72 mmol) of compound 17 followed by 1.4 mL (24.8mmol) of acetic acid and 156 mg (2.48 mmol) of sodium cyanoborohydride. The resulting mixture20 was stirred at room temperature for 2 hours. The solvent was removed in vacuo. The residue wasadjusted to pH 8 by sodium bicarbonate and extracted with DCM, washed with brine, dried oversodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash columnchromatography using SiliaSep Cartridges ( 40g), eluting with 0-5% methanol/DCM to give 680mg(51%) of compound 19-6. MS (ESI) m/z 538 [M+2H], 1075 [M+H].