O-Propanoyloxymethyl S-Ethyl Carbonothioate

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

Procedure: Thionyl chloride (101 μL, 1.25 mmol) was added drop-wise to a solution of 53 (160 mg, 0.832 mmol) in CH2Cl2 (0.5 mL) at 0° C. then the solution was stirred for a further 1.5 hr. The solvent was removed under reduced pressure resulting in the volatile chloroformate 54 (138 mg, 100%). 1H NMR (400 MHz, CDCl3) δ 1.18 (t, J=7.4, 3H), 2.45 (q, J=7.4, 2H), 5.83 (s, 2H). The solvent was removed under reduced pressure

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

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

Procedure: Thionyl chloride (101 μL, 1.25 mmol) was added drop-wise to a solution of 53 (160 mg, 0.832 mmol) in CH2Cl2 (0.5 mL) at 0° C. then the solution was stirred for a further 1.5 hr. The solvent was removed under reduced pressure resulting in the volatile chloroformate 54 (138 mg, 100%). 1H NMR (400 MHz, CDCl3) δ 1.18 (t, J=7.4, 3H), 2.45 (q, J=7.4, 2H), 5.83 (s, 2H). The solvent was removed under reduced pressure

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

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

Procedure: Thionyl chloride (101 μL, 1.25 mmol) was added drop-wise to a solution of 53 (160 mg, 0.832 mmol) in CH2Cl2 (0.5 mL) at 0° C. then the solution was stirred for a further 1.5 hr. The solvent was removed under reduced pressure resulting in the volatile chloroformate 54 (138 mg, 100%). 1H NMR (400 MHz, CDCl3) δ 1.18 (t, J=7.4, 3H), 2.45 (q, J=7.4, 2H), 5.83 (s, 2H). The solvent was removed under reduced pressure

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

Procedure: To a stirred solution of NaHCO3 (45 g, 536 mmol) in H2O (540 ml) is added TBA HSO4 (91.2 g, 268 mmol), propanoic acid (20.1 mL, 268 mmol), and CH2Cl2 (540 ml). Following stirring for 1 h at room temperature a solution of 5b (49.2 g, 200 mmol) in CH2Cl2 (100 mL) is added during 45 min keeping the temperature below 30° C. The stirring is continued for 11/2 h. The organic phase is separated, washed with H2O (200 mL), dried (MgSO4), and evaporated. The residue is stirred in Et2O (800 mL) during the night, filtered, and washed with Et2O (50 mL). The filtrate is evaporated and distilled to yield 38.0 g (98%) of 6cb, bp 71°-73° C./0.3 mbar. is added during 45 min the temperature below 30° C 2 h The organic phase is separated washed with H2O (200 mL) dried (MgSO4) evaporated filtered washed with Et2O (50 mL) The filtrate is evaporated distilled