Hydrochloric Acid → Thioacetic acid S-[(E)-4-((3S,7R,10R,13R,14S)-14-hydroxy-7,13-diisopropyl-10-methyl-5,8,11,16-tetraoxo-1,2-dioxa-6,9,12-triaza-cyclohexadec-3-yl)-but-3-enyl]ester

Participants

Reaction Steps

To a solution of 9 (24.7 mg, 0.035 mmol) in CH2Cl2 (1.4 mL) was added triethylsilane (28 μL, 0.175 mmol) followed by the dropwise addition of TFA (0.35 mL, 25% v/v). After stirring for 1 h the reaction mixture was concentrated in vacuo and put under high vacuum for 2 h to give the crude thiol 10. At 0° C. to a solution of thiol 10 in CH2Cl2 (0.45 mL) was added diisopropylethylamine (30 μL, 0.172 mmol) followed by acetyl chloride (2.43 μL, 0.034 mmol) in CH2Cl2 (0.1 mL). After stirring for 2 h 10 min 1M HCl (1 mL) was added followed by EtOAc (10 mL) the layers were separated and the organic layer was washed with sat. brine (10 mL). The organic layer was dried (MgSO4) and concentrated in vacuo. Purification by flash column chromatography (eluent 1:0-98:2-96:4-94:6-92.8 CH2Cl2/MeOH) gave the product 11 (7.3 mg, 0.014 mmol, 41%) as a white solid: Rf 0.47 MeOH/CH2Cl2 (1:9).

Provenance & Evidence