2-hydroxy-2,4-dimethylpentan-3-one

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

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

Procedure: To a solution of 2.14 g. (5.0 mmole) beta-benzyl-N-benzyloxycarbonyl-L-aspartyl-D-alanine in 35 ml. tetrahydrofuran cooled to -15° was added 0.55 ml. (5.0 mmole) N-methylmorpholine and 0.48 ml. (5.0 mmole) ethyl chloroformate. The mixture was stirred at -15° to -10° C. for two minutes and 0.66 g. (5.0 mmole) 3-amino-2-hydroxy-2,4-dimethylpentane was added. The mixture was allowed to warm to room temperature, stirred overnight and worked-up as described in Example 5, Part B, to obtain the diprotected dipeptide amide, Rf 0.27 (TLC, ethyl acetate/hexane, 1:1, phosphomolybdic acid spray, heat) which was used directly in the next step. was added 0.55 ml stirred overnight to obtain

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

Procedure: To a stirred solution of 28.3 ml. (0.2 mole) 2,4-dimethyl-3-pentanone in 100 ml. chloroform was added dropwise 10.3 ml. (0.2 mole) bromine in 30 ml. of the same solvent. The resulting mixture was stirred for a few minutes, the solvent evaporated in vacuo, the residue taken up in 100 ml. ethanol. Water, 50 ml., and 10 M sodium hydroxide, 50 ml., added. The resulting mixture was stirred at reflux for one hour, diluted with 200 ml. water and extracted with 3×50 ml. ethyl ether. The extracts were dried (MgSO4) evaporated to dryness and the residue distilled to obtain 15.95 g. (61%) of the hydroxy-ketone, b.p. 60°-62° C./18 mm. the solvent evaporated in vacuo , added The resulting mixture was stirred at reflux for one hour diluted with 200 ml water and extracted with 3×50 ml The extracts were dried (MgSO4) evaporated to dryness the residue distilled to obtain 15.95 g

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

Procedure: To a stirred solution of 28.3 ml. (0.2 mole) 2,4-dimethyl-3-pentanone in 100 ml. chloroform was added dropwise 10.3 ml. (0.2 mole) bromine in 30 ml. of the same solvent. The resulting mixture was stirred for a few minutes, the solvent evaporated in vacuo, the residue taken up in 100 ml. ethanol. Water, 50 ml., and 10M sodium hydroxide, 50 ml., added. The resulting mixture was stirred at reflux for one hour, diluted with 200 ml. water and extracted with 3×50 ml. ethyl ether. The extracts were dried (MgSO4) evaporated to dryness and the residue distilled to obtain 15.95 g. (61%) of the hydroxy-ketone, b.p. 60°-62° C./18 mm. the solvent evaporated in vacuo , added The resulting mixture was stirred at reflux for one hour diluted with 200 ml water and extracted with 3×50 ml The extracts were dried (MgSO4) evaporated to dryness the residue distilled to obtain 15.95 g

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

Procedure: To a stirred solution of 28.3 ml. (0.2 mole) 2,4-dimethyl-3-pentanone in 100 ml. chloroform was added dropwise 10.3 ml. (0.2 mole) bromine in 30 ml. of the same solvent. The resulting mixture was stirred for a few minutes, the solvent evaporated in vacuo, the residue taken up in 100 ml. ethanol. Water, 50 ml., and 10M sodium hydroxide, 50 ml., added. The resulting mixture was stirred at reflux for one hour, diluted with 200 ml. water and extracted with 3×50 ml. ethyl ether. The extracts were dried (MgSO4) evaporated to dryness and the residue distilled to obtain 15.95 g. (61%) of the hydroxy-ketone, b.p. 60°-62° C./18 mm. the solvent evaporated in vacuo , added The resulting mixture was stirred at reflux for one hour diluted with 200 ml water and extracted with 3×50 ml The extracts were dried (MgSO4) evaporated to dryness the residue distilled to obtain 15.95 g

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

Procedure: To a stirred solution of 28.3 ml. (0.2 mole) 2,4-dimethyl-3-pentanone in 100 ml. chloroform was added dropwise 10.3 ml. (0.2 mole) bromine in 30 ml. of the same solvent. The resulting mixture was stirred for a few minutes, the solvent evaporated in vacuo, the residue taken up in 100 ml. ethanol. Water, 50 ml., and 10 M sodium hydroxide, 50 ml., added. The resulting mixture was stirred at reflux for one hour, diluted with 200 ml. water and extracted with 3×50 ml. ethyl ether. The extracts were dried (MgSO4) evaporated to dryness and the residue distilled to obtain 15.95 g. (61%) of the hydroxy-ketone, b.p. 60°-62° C./18 mm. the solvent evaporated in vacuo , added The resulting mixture was stirred at reflux for one hour diluted with 200 ml water and extracted with 3×50 ml The extracts were dried (MgSO4) evaporated to dryness the residue distilled to obtain 15.95 g

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

Procedure: To a stirred solution of 28.3 ml. (0.2 mole) 2,4-dimethyl-3-pentanone in 100 ml. chloroform was added dropwise 10.3 ml. (0.2 mole) bromine in 30 ml. of the same solvent. The resulting mixture was stirred for a few minutes, the solvent evaporated in vacuo, the residue taken up in 100 ml. ethanol. Water, 50 ml., and 10 M sodium hydroxide, 50 ml., added. The resulting mixture was stirred at reflux for one hour, diluted with 200 ml. water and extracted with 3×50 ml. ethyl ether. The extracts were dried (MgSO4) evaporated to dryness and the residue distilled to obtain 15.95 g. (61%) of the hydroxy-ketone, b.p. 60°-62° C./18 mm. the solvent evaporated in vacuo , added The resulting mixture was stirred at reflux for one hour diluted with 200 ml water and extracted with 3×50 ml The extracts were dried (MgSO4) evaporated to dryness the residue distilled to obtain 15.95 g

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

Procedure: To a solution of 2.14 g. (5.0 mmole) beta-benzyl-N-benzyloxycarbonyl-L-aspartyl-D-alanine in 35 ml. tetrahydrofuran cooled to -15° was added 0.55 ml. (5.0 mmole) N-methylmorpholine and 0.48 ml. (5.0 mmole) ethyl chloroformate. The mixture was stirred at -15° to -10° C. for two minutes and 0.66 g. (5.0 mmole) 3-amino-2-hydroxy-2,4-dimethylpentane was added. The mixture was allowed to warm to room temperature, stirred overnight and worked-up as described in Example 5, Part B, to obtain the diprotected dipeptide amide, Rf 0.27 (TLC, ethyl acetate/hexane, 1:1, phosphomolybdic acid spray, heat) which was used directly in the next step. was added 0.55 ml stirred overnight to obtain

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

Procedure: To a solution of 2.14 g. (5.0 mmole) beta-benzyl-N-benzyloxycarbonyl-L-aspartyl-D-alanine in 35 ml. tetrahydrofuran cooled to -15° was added 0.55 ml. (5.0 mmole) N-methylmorpholine and 0.48 ml. (5.0 mmole) ethyl chloroformate. The mixture was stirred at -15° to -10° C. for two minutes and 0.66 g. (5.0 mmole) 3-amino-2-hydroxy-2,4-dimethylpentane was added. The mixture was allowed to warm to room temperature, stirred overnight and worked-up as described in Example 5, Part B, to obtain the diprotected dipeptide amide, Rf 0.27 (TLC, ethyl acetate/hexane, 1:1, phosphomolybdic acid spray, heat) which was used directly in the next step. was added 0.55 ml stirred overnight to obtain

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

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

Procedure: To a stirred solution of 28.3 ml. (0.2 mole) 2,4-dimethyl-3-pentanone in 100 ml. chloroform was added dropwise 10.3 ml. (0.2 mole) bromine in 30 ml. of the same solvent. The resulting mixture was stirred for a few minutes, the solvent evaporated in vacuo, the residue taken up in 100 ml. ethanol. Water, 50 ml., and 10M sodium hydroxide, 50 ml., added. The resulting mixture was stirred at reflux for one hour, diluted with 200 ml. water and extracted with 3×50 ml. ethyl ether. The extracts were dried (MgSO4) evaporated to dryness and the residue distilled to obtain 15.95 g. (61%) of the hydroxy-ketone, b.p. 60°-62° C./18 mm. the solvent evaporated in vacuo , added The resulting mixture was stirred at reflux for one hour diluted with 200 ml water and extracted with 3×50 ml The extracts were dried (MgSO4) evaporated to dryness the residue distilled to obtain 15.95 g

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

Procedure: To a stirred solution of 28.3 ml. (0.2 mole) 2,4-dimethyl-3-pentanone in 100 ml. chloroform was added dropwise 10.3 ml. (0.2 mole) bromine in 30 ml. of the same solvent. The resulting mixture was stirred for a few minutes, the solvent evaporated in vacuo, the residue taken up in 100 ml. ethanol. Water, 50 ml., and 10 M sodium hydroxide, 50 ml., added. The resulting mixture was stirred at reflux for one hour, diluted with 200 ml. water and extracted with 3×50 ml. ethyl ether. The extracts were dried (MgSO4) evaporated to dryness and the residue distilled to obtain 15.95 g. (61%) of the hydroxy-ketone, b.p. 60°-62° C./18 mm. the solvent evaporated in vacuo , added The resulting mixture was stirred at reflux for one hour diluted with 200 ml water and extracted with 3×50 ml The extracts were dried (MgSO4) evaporated to dryness the residue distilled to obtain 15.95 g