tert-butyl 2-[(4R,6R)-6-(cyanomethyl)-2,2-dimethyl-1,3-dioxan-4-yl]acetate

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

Procedure: A solution of (4R-cis)-1,1-dimethylethyl 6-cyanomethyl-2,2-dimethyl-1,3-dioxane-4 -acetate, 5.63 g (0.048 mol), in 100 mL of methanol saturated with gaseous ammonia is treated with 0.5 g of Raney nickel #30 and hydrogen gas in a shaker at 50 psi and 40 ° C. After 16 hours, thin layer chromatography indicates no starting nitrile present. The suspension is cooled, filtered through filter aid, and concentrated to an oil. This crude oil is purified by flash chromatography on silica gel with 30:20:1 (ethyl acetate:methanol:ammonium hydroxide) as eluent to give 4.93 g of (4R-cis)-1,1-dimethylethyl 6-(2-aminoethyl)-2,2-dimethyl-1,3-dioxane-4-acetate (98.2 area %) as a clear oil with acceptable IR, NMR, C-NMR and MS spectra. The suspension is cooled filtered through filter aid concentrated to an oil This crude oil is purified by flash chromatography on silica gel with 30:20:1 (ethyl acetate:methanol:ammonium hydroxide) as eluent

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

Procedure: Crude [R-(R*,R*)]-1,1-dimethylethyl 6-cyano-3,5-dihydroxyhexanoate, 15 g (61 mol), is dissolved in 150 mL of 2,2-dimethoxypropane, camphorsulfonic acid is added, and the solution is stirred for 18 hours at room temperature, concentration and flash chromatography after concentration in vacuo provides 11.8 g of (4R-cis)-1,1-dimethylethyl 6-cyanomethyl-2,2-dimethyl-1,3-dioxane-4-acetate as an off-white solid, mp 64.7°-68° C. with acceptable IR, NMR, C-NMR and analysis. concentration and flash chromatography after concentration in vacuo

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (±)-cis-6-(cyanomethyl)-2,2-dimethyl-1,3-dioxane-4-acetic acid (3.72 g, 17.44 mmol) is dissolved in 20 mL of dichloromethane, cooled to 0° C. and 0.2 g of 4-dimethylaminopyridine (DMAP) is added, followed by t-butyl alcohol and followed by 4.32 g of dicyclohexylcarbodiimide (DCC). This solution is allowed to slowly warm to room temperature over a 76.5-hour period. Thin layer chromotography (TLC) shows mainly product, and some slightly lower Rf by-products. The mixture is stirred one hour and 50 mL of dichloromethane is added and stirring continues five hours. An additional 100 mL of diethyl ether is added and the mixture filtered. The precipitate is washed with diethyl ether. The filtrate is concentrated to an oil. The crude product is chromatographed on silica gel eluting with 4:1 hexane:ethyl acetate. The eluate is concentrated to yield (±)-cis-1,1-dimethylethyl 6-(cyanomethyl)-2,2-dimethyl-1,3-dioxane-4-acetate. to slowly warm to room temperature over a 76.5-hour period stirring continues five hours the mixture filtered The precipitate is washed with diethyl ether The filtrate is concentrated to an oil The crude product is chromatographed on silica gel eluting with 4:1 hexane The eluate is concentrated

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

Procedure: Crude [R—(R*,R*)]-1,1-dimethylethyl 6-cyano-3,5-dihydroxyhexanoate (about 150 moles) from Step (2) is diluted with 100 kg of 2,2-dimethoxypropane and acidified with about 1 L of methanesulfonic acid. The reaction is quenched by the addition of aqueous sodium bicarbonate solution and concentrated by vacuum distillation. The residue is diluted with 150 L of hexane, and the layers separated. The organic layer is washed with aqueous sodium bicarbonate solution and cooled to 0° C.±10° C. to crystallize. The product is collected by filtration and washed with cooled hexane, then dried affording 28.5 kg of (4R cis) 1,1-dimethylethyl 6-cyanomethyl-2,2-dimethyl-1,3-dioxane-4-acetate. The reaction is quenched by the addition of aqueous sodium bicarbonate solution concentrated by vacuum distillation The residue is diluted with 150 L of hexane the layers separated The organic layer is washed with aqueous sodium bicarbonate solution cooled to 0° C.±10° C. to crystallize The product is collected by filtration washed with cooled hexane dried

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

Procedure: A solution of (4R-cis)-1,1-dimethylethyl 6-cyanomethyl-2,2-dimethyl-1,3-dioxane-4-acetate, (Example 1) 5.63 g (0.048 mol), in 100 mL of methanol saturated with gaseous ammonia is treated with 0.5 g of Raney nickel 190 30 and hydrogen gas in a shaker at 50 pounds per square inch (psi) and 40° C. After 16 hours, thin layer chromatography indicates no starting nitrile present. The suspension is cooled, filtered through filter aid, and concentrated to an oil. This crude oil is purified by flash chromatography on silica gel with 30:20:1 (ethyl acetate:methanol:ammonium hydroxide) as eluant to give 4.93 g of (4R-cis)-1,1-dimethylethyl 6-(2-aminoethyl)- 2,2-dimethyl-1,3-dioxane-4-acetate (98.2 area %) as a clear oil. The suspension is cooled filtered through filter aid concentrated to an oil This crude oil is purified by flash chromatography on silica gel with 30:20:1 (ethyl acetate:methanol:ammonium hydroxide) as eluant

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

Procedure: Crude [R-(R*,R*)]-1,1-dimethylethyl 6-cyano-3,5-dihydroxyhexanoate, 15 g (61 mol), is dissolved in 150 mL of 2,2-dimethoxypropane, camphorsulfonic acid is added, and the solution is stirred for 18 hours at room temperature. Concentration and flash chromatography after concentration in vacuo provides 11.8 g of (4R-cis)-1,1-dimethylethyl 6-cyanomethyl-2,2-dimethyl-1,3-dioxane-4-acetate as an off-white solid, mp 64.7°-68° C. with acceptable IR, NMR, C-NMR and analysis. Concentration and flash chromatography after concentration in vacuo

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (±)-cis-6-(cyanomethyl)-2,2-dimethyl-1,3-dioxane-4-acetic acid (3.72 g, 17.44 mmol) is dissolved in 20 mL of dichloromethane, cooled to 0° C. and 0.2 g of 4-dimethylaminopyridine (DMAP) is added, followed by t-butyl alcohol and followed by 4.32 g of dicyclohexylcarbodiimide (DCC). This solution is allowed to slowly warm to room temperature over a 76.5-hour period. Thin layer chromotography (TLC) shows mainly product, and some slightly lower Rf by-products. The mixture is stirred one hour and 50 mL of dichloromethane is added and stirring continues five hours. An additional 100 mL of diethyl ether is added and the mixture filtered. The precipitate is washed with diethyl ether. The filtrate is concentrated to an oil. The crude product is chromatographed on silica gel eluting with 4:1 hexane:ethyl acetate. The eluate is concentrated to yield (±)-cis-1,1-dimethyl-ethyl 6-(cyanomethyl)-2,2-dimethyl-1,3-dioxane-4-acetate. to slowly warm to room temperature over a 76.5-hour period stirring continues five hours the mixture filtered The precipitate is washed with diethyl ether The filtrate is concentrated to an oil The crude product is chromatographed on silica gel eluting with 4:1 hexane The eluate is concentrated

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of (4R-cis)-1,1-dimethylethyl 6-cyanomethyl-2,2-dimethyl-1,3-dioxane-4-acetate (Example 5), 8.2 kg (30.5 mol) in 100 L of methanol containing 15 kg of anhydrous ammonia was reacted with hydrogen gas under 50 pounds per square inch (psi) at 30° C. in the presence of a slurry of 8 kg of Raney nickel doped with 1% molybdenum. After 6 hours, uptake of hydrogen had ceased, the mixture was cooled to 20° C., the atmosphere was vented and exchanged for nitrogen, and the slurry was filtered, concentrated by distillation and distilled under vacuum to give 7.8 kg of 96% pure (4R-cis)-1,1-dimethylethyl 6-(2-aminoethyl)-2,2-dimethyl-1,3-dioxane-4-acetate as a clear oil; bp 125-135° C. at 0.5 mm Hg. the slurry was filtered concentrated by distillation distilled under vacuum

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of (4R-cis)-1,1 dimethylethyl 6-cyanomethyl-2,2-dimethyl-1,3-dioxane-4-acetate (Example 2), 8.2 kg (30.5 mol) in 100 L of methanol containing 15 kg of anhydrous ammonia is reacted with hydrogen gas under 50 pounds per square inch (psi) at 30° C. in the presence of a slurry of 8 kg of Raney nickel doped with 1% molybdenum. After 6 hours, uptake of hydrogen has ceased, the mixture is cooled to 20° C., the atmosphere is vented and exchanged for nitrogen, and the slurry is filtered, concentrated by distillation and distilled under vacuum to give 7.8 kg of 96% pure (4R-cis)-1,1-dimethylethyl 6-(2-aminoethyl)-2,2-dimethyl-1,3-dioxane-4-acetate as a clear oil; bp 125°-135° C. @0.5 mm Hg. 200 MHz 1H-NMR (CDCl3) 1.0-1.2 (m, 1H), 1.22 (s, 3H), 1.31 (s, 12H), 1.35-1.45 (m, 3H), 2.15 (dd, 1H, J=15.1 Hz, J=6.2 Hz), 2.29 (dd, 1H, J=15.1Hz, J=7.0 Hz), 2.66 (t, 2H, J=6.6 Hz), 3.82 (m, 1H), 4.12 (m, 1H). the slurry is filtered concentrated by distillation distilled under vacuum

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of (4R-cis)-1,1 dimethylethyl 6-cyanomethyl-2,2-dimethyl-1,3-dioxane-4-acetate (Example 2), 8.2 kg (30.5 mol) in 100 L of methanol containing 15 kg of anhydrous ammonia is reacted with hydrogen gas under 50 pounds per square inch (psi) at 30° C. in the presence of a slurry of 8 kg of Raney nickel doped with 1% molybdenum. After 6 hours, uptake of hydrogen has ceased, the mixture is cooled to 20° C., the atmosphere is vented and exchanged for nitrogen, and the slurry is filtered, concentrated by distillation and distilled under vacuum to give 7.8 kg of 96% pure (4R-cis)-1,1-dimethylethyl 6-(2-aminoethyl)-2,2-dimethyl-1,3-dioxane-4-acetate as a clear oil; bp 125°-135° C. @0.5 mm Hg. 200 MHz 1H-NMR (CDCl3) 1.0-1.2 (m, 1H), 1.22 (s, 3H), 1.31 (s, 12H), 1.35-1.45 (m, 3H), 2.15 (dd, 1H, J=15.1 Hz, J=6.2 Hz), 2.29 (dd, 1H, J=15.1Hz, J=7.0 Hz), 2.66 (t, 2H, J=6.6 Hz), 3.82 (m, 1H), 4.12 (m, 1H). the slurry is filtered concentrated by distillation distilled under vacuum

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

Procedure: A solution of (4R-cis)-1,1-dimethylethyl 6-cyanomethyl-2,2-dimethyl-1,3-dioxane-4 -acetate, 5.63 g (0.048 mol), in 100 mL of methanol saturated with gaseous ammonia is treated with 0.5 g of Raney nickel #30 and hydrogen gas in a shaker at 50 psi and 40 ° C. After 16 hours, thin layer chromatography indicates no starting nitrile present. The suspension is cooled, filtered through filter aid, and concentrated to an oil. This crude oil is purified by flash chromatography on silica gel with 30:20:1 (ethyl acetate:methanol:ammonium hydroxide) as eluent to give 4.93 g of (4R-cis)-1,1-dimethylethyl 6-(2-aminoethyl)-2,2-dimethyl-1,3-dioxane-4-acetate (98.2 area %) as a clear oil with acceptable IR, NMR, C-NMR and MS spectra. The suspension is cooled filtered through filter aid concentrated to an oil This crude oil is purified by flash chromatography on silica gel with 30:20:1 (ethyl acetate:methanol:ammonium hydroxide) as eluent

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

Procedure: Crude [R-(R*,R*)]-1,1-dimethylethyl 6-cyano-3,5-dihydroxyhexanoate, 15 g (61 mol), is dissolved in 150 mL of 2,2-dimethoxypropane, camphorsulfonic acid is added, and the solution is stirred for 18 hours at room temperature, concentration and flash chromatography after concentration in vacuo provides 11.8 g of (4R-cis)-1,1-dimethylethyl 6-cyanomethyl-2,2-dimethyl-1,3-dioxane-4-acetate as an off-white solid, mp 64.7°-68° C. with acceptable IR, NMR, C-NMR and analysis. concentration and flash chromatography after concentration in vacuo