benzyl 2-hydroxypropanoate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:-15.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Construction of Benzyl-L-lactic Acid. L-Lactic acid (9 g, 100 mmol) is added to N,N'-diisopropylbenzylisourea (23.3 g, 100 mmol) with stirring. The mixture becomes very viscous within 10 min and is stirred intermittently for 1 h. The volume is then increased to 200 mL with THF, and the mixture stirred for 48 h at room temperature. After cooling the mixture to -15° C., the diisopropylurea is removed by filtration and the THF is evaporated under reduced pressure. The resulting thick oil is pumped under high vacuum for 24 h to give benzyl lactate (17.4 g, 95%) which may be used without further purification. is stirred intermittently for 1 h the mixture stirred for 48 h at room temperature the diisopropylurea is removed by filtration the THF is evaporated under reduced pressure The resulting thick oil is pumped under high vacuum for 24 h

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:-15.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Construction of Benzyl-L-lactic Acid. L-Lactic acid (9 g, 100 mmol) is added to N,N'-diisopropylbenzylisourea (23.3 g, 100 mmol) with stirring. The mixture becomes very viscous within 10 min and is stirred intermittently for 1 h. The volume is then increased to 200 mL with THF, and the mixture stirred for 48 h at room temperature. After cooling the mixture to -15° C., the diisopropylurea is removed by filtration and the THF is evaporated under reduced pressure. The resulting thick oil is pumped under high vacuum for 24 h to give benzyl lactate (17.4 g, 95%) which may be used without further purification. is stirred intermittently for 1 h the mixture stirred for 48 h at room temperature the diisopropylurea is removed by filtration the THF is evaporated under reduced pressure The resulting thick oil is pumped under high vacuum for 24 h

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Reaction Scheme A above begins with the triflate of a carboxyl-protected D-αhydroxycarboxylic acid derivative, e.g., lactic acid benzyl ester. By reacting this triflate with α-ethyl-γ-anilido-L-glutamate (prepared, for example, by reacting an amino-protected L-glutamic acid, such as Nα -Cbo-L-glutamic acid, with diethyl sulfate in triethylamine and dichloromethane at room temperature for about three days to give Nα -Cbo-α-ethyl-L-glutamate, forming the dicyclohexylamine salt of the thus-obtained glutamate by reaction with dicyclohexylamine in ethyl acetate at room temperature overnight, acidifying a suspension of the dicyclohexylamine salt and then reacting the isolated free acid with dicyclohexylcarbodiimide and aniline in dichloromethane, first in a dry ice/ice/acetone bath for one hour, and then at room temperature overnight), Nα -[1(L)-carbethoxy-3-carboxanilidopropyl]-L alanine benzyl ester is obtained. Reaction Scheme A

Conditions: temp:-15.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Construction of Benzyl-L-lactic Acid. L-Lactic acid (9 g, 100 mmol) is added to N,N'-diisopropylbenzylisourea (23.3 g, 100 mmol) with stirring. The mixture becomes very viscous within 10 min and is stirred intermittently for 1 h. The volume is then increased to 200 mL with THF, and the mixture stirred for 48 h at room temperature. After cooling the mixture to -15° C., the diisopropylurea is removed by filtration and the THF is evaporated under reduced pressure. The resulting thick oil is pumped under high vacuum for 24 h to give benzyl lactate (17.4 g, 95%) which may be used without further purification. is stirred intermittently for 1 h the mixture stirred for 48 h at room temperature the diisopropylurea is removed by filtration the THF is evaporated under reduced pressure The resulting thick oil is pumped under high vacuum for 24 h