2-methylpropyl (2R)-2-(oxan-2-yloxy)propanoate

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

Procedure: A mixture of isobutyl (R)-lactate (73 g, 0.5 mol, Merck) and 3,4-dihydro-2H-pyran (70 g, 0.83 mol, Merck) was treated with 5M hydrogen chloride in dimethylformamide (4 ml) and set aside at ambient temperature overnight in calcium chloride protected 250 ml round-bottom flask. Silver oxide (15 g) was added, the mixture stirred magnetically for 2 hours and then filtered. The product was isolated by distillation (13 Pa, b.p. 94-96° C.) to provide isobutyl 2-O-tetrahydropyranyl-(R)-lactate (102.5 g, 89%) as a colorless oil. filtered The product was isolated by distillation (13 Pa, b.p. 94-96° C.)

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

Procedure: A mixture of isobutyl (R)-lactate (73 g, 0.5 mol, Merck) and 3,4-dihydro-2H-pyran (70 g, 0.83 mol, Merck) was treated with 5M hydrogen chloride in dimethylformamide (4 ml) and set aside at ambient temperature overnight in calcium chloride protected 250 ml round-bottom flask. Silver oxide (15 g) was added, the mixture stirred magnetically for 2 hours and then filtered. The product was isolated by distillation (13 Pa, b.p. 94-96° C.) to provide isobutyl 2-O-tetrahydropyranyl-(R)-lactate (102.5 g, 89%) as a colorless oil. filtered The product was isolated by distillation (13 Pa, b.p. 94-96° C.)

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

Procedure: A mixture of isobutyl (R)-lactate (73 g, 0.5 mol, Merck) and 3,4-dihydro-2H-pyran (70 g, 0.83 mol, Merck) was treated with 5M hydrogen chloride in dimethylformamide (4 ml) and set aside at ambient temperature overnight in calcium chloride protected 250 ml round-bottom flask. Silver oxide (15 g) was added, the mixture stirred magnetically for 2 hours and then filtered. The product was isolated by distillation (13 Pa, b.p. 94∝96° C.) to provide isobutyl 2-O-tetrahydropyranyl-(R)-lactate (102.5 g, 89%) as a colorless oil. filtered The product was isolated by distillation (13 Pa, b.p. 94∝96° C.)

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

Procedure: A mixture of isobutyl (R)-lactate (73 g, 0.5 mol, Merck) and 3,4-dihydro-2H-pyran (70 g, 0.83 mol, Merck) was treated with 5M hydrogen chloride in dimethylformamide (4 ml) and set aside at ambient temperature overnight in calcium chloride protected 250 ml round-bottom flask. Silver oxide (15 g) was added, the mixture stirred magnetically for 2 hours and then filtered. The product was isolated by distillation (13 Pa, b.p. 94∝96° C.) to provide isobutyl 2-O-tetrahydropyranyl-(R)-lactate (102.5 g, 89%) as a colorless oil. filtered The product was isolated by distillation (13 Pa, b.p. 94∝96° C.)

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

Procedure: 21.8 g (0.26 mole) of 3,4-dihydro-2H-pyran was dropwise added at room temperature to a mixture of 29.2 g (0.2 mole) of isobutyl (R)-(+)-lactate and 0.3 g of phosphorus oxychloride. After the completion of the dropwise addition, the resulting mixture was stirred at room temperature for 4 hours. After the reaction, 100 ml of ethyl acetate was added, followed by washing with 70 ml of a saturated aqueous sodium hydrogen carbonate solution, 70 ml of water and 70 ml of a saturated aqueous sodium chloride solution in this order. The washed material was dried over anhydrous sodium sulfate and then subjected to vacuum distillation to remove the solvent, whereby was obtained 49.0 g (yield: 92.1%) of an oily title compound (diastereomixture). After the completion of the dropwise addition was added by washing with 70 ml of a saturated aqueous sodium hydrogen carbonate solution, 70 ml of water and 70 ml of a saturated aqueous sodium chloride solution in this order The washed material was dried over anhydrous sodium sulfate subjected to vacuum distillation to remove the solvent

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

Procedure: A mixture of isobutyl (R)-lactate (73 g, 0.5 mol, Merck) and 3,4-dihydro-2H-pyran (70 g, 0.83 mol, Merck) was treated with 5M hydrogen chloride in dimethylformamide (4 ml) and set aside at ambient temperature overnight in calcium chloride protected 250 ml round-bottom flask. Silver oxide (15 g) was added, the mixture stirred magnetically for 2 hours and then filtered. The product was isolated by distillation (13 Pa, b.p. 94-96° C.) to provide isobutyl 2-O-tetrahydropyranyl-(R)-lactate (102.5 g, 89%) as a colorless oil. filtered The product was isolated by distillation (13 Pa, b.p. 94-96° C.)

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

Procedure: A mixture of isobutyl (R)-lactate (73 g, 0.5 mol, Merck) and 3,4-dihydro-2H-pyran (70 g, 0.83 mol, Merck) was treated with 5M hydrogen chloride in dimethylformamide (4 ml) and set aside at ambient temperature overnight in calcium chloride protected 250 ml round-bottom flask. Silver oxide (15 g) was added, the mixture stirred magnetically for 2 hours and then filtered. The product was isolated by distillation (13 Pa, b.p. 94∝96° C.) to provide isobutyl 2-O-tetrahydropyranyl-(R)-lactate (102.5 g, 89%) as a colorless oil. filtered The product was isolated by distillation (13 Pa, b.p. 94∝96° C.)