Triphenylphosphine → HCID 131720214, compound

Participants

Reaction Steps

A 0° C. solution of triphenylphosphine (1.26 g., 4.79 mmol., 1.5 eq.) in dry tetrahydrofuran (15 ml.) was treated with diisopropyl azodicarboxylate (943 μl., 4.79 mmol.). The resultant white slurry was stirred for 30 minutes and then treated with a solution of [S-(R*,R*)]-2-[(2-phthalimido-4-hydroxy-1-oxobutyl)amino]-5,5-dimethoxypentanoic acid, methyl ester [prepared as described in Example 4(i), 1,35 g., 3.20 mmol.]in dry tetrahydrofuran (15 ml.) followed by neat thiolacetic acid (343 μl., 4.79 mmol.). The mixture was stirred at 0° C. for 1.5 hours and then partitioned between ethyl acetate (150 ml.) and 50% sodium bicarbonate (100 ml.). The ethyl acetate layer was washed with brine, dried over magnesium sulfate, filtered, concentrated, adsorbed onto Celite® and dried in vacuo. The crude material was purified by chromatography on a 2.5×15 cm silica gel column eluting with 1:1 ethyl acetate:hexane (11.) and 6:4 ethyl acetate:hexane (11.). The desired fractions were combined, concentrated and dried in vacuo affording 1.35 g. of title produce as an oil. TLC (8:2, ethyl acetate:hexane) Rf =0.42.

Provenance & Evidence