(3aR,6aR)-2,2-dimethyl-3a,5,6,6a-tetrahydrocyclopenta[d][1,3]dioxol-4-one

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

Procedure: (3 aR,6aR)-2,2-dimethyldihydro-3 aH-cyclopenta[d][1,3]dioxol-4(5H)-one (1-2) (2.75 g, 17.6 mmol, 1 equiv) was dissolved in methanol (166 mL) and sodium borohydride (1.0 g, 26.4 mmol, 1.5 equiv) was added portion wise at 0° C. Upon disappearance of the starting material as monitored by LC-MS analysis, water was added and the mixture was concentrated. The aqueous phase was extracted with DCM (3×100 mL), the combined organics were dried (Na2SO4), and the solvent was removed to afford (3AS,4S,6aR)-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (1-3) as a colorless oil that did not require further purification. was added the mixture was concentrated The aqueous phase was extracted with DCM (3×100 mL) the combined organics were dried (Na2SO4) the solvent was removed

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

Procedure: (3aS,4S,6aR)-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (1-1) (10 g, 64.0 mmol, 1 equiv) was dissolved in MeOH (200 mL), the system was placed under nitrogen and 10% Pd/C (681 mg, 6.4 mmol, 0.1 equiv) was carefully added. The resulting mixture was stirred under a H2 atmosphere (1 atm) until disappearance of the starting material as monitored by LC-MS analysis. Hydrogen was removed followed by filtration through a celite plug and washing of the solids with MeOH (4×75 mL). The filtrate was concentrated and the residue was purified via flash chromatography on a 120 g silica gel column (gradient elution 0 to 50% ethyl acetate in hexanes) to yield (3aR,6aR)-2,2-dimethyldihydro-3aH-cyclopenta[d][1,3]dioxol-4(5H)-one (1-2) as a white fluffy solid and (3aS,4S,6aR)-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (1-3) as a colorless oil. 1H NMR (1-2) (500 MHz, CDCl3): δ 4.84 (t, J=4.8 Hz, 1H); 4.19 (d, J=5.2 Hz, 1H); 2.65-2.53 (m, 1H); 2.33-2.23 (m, 2H); 2.11-2.01 (m, 1H); 1.43 (s, 3H); 1.38-1.31 (m, 3 II). 1H NMR (1-3) (400 MHz, CDCl3): δ 4.61 (t, J=5.3 Hz, 1H); 4.40 (t, J=5.6 Hz, 1H); 3.88-3.77 (m, 1H); 2.43 (d, J=9.9 Hz, 1H); 1.93-1.75 (m, 2H); 1.70-1.55 (m, 1H); 1.49 (s, 3H); 1.47-1.35 (m, 1H); 1.34 (s, 3H). Hydrogen was removed followed by filtration through a celite plug washing of the solids with MeOH (4×75 mL) The filtrate was concentrated the residue was purified via flash chromatography on a 120 g silica gel column (gradient elution 0 to 50% ethyl acetate in hexanes)

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

Procedure: (3aS,4S,6aR)-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (1-1) (10 g, 64.0 mmol, 1 equiv) was dissolved in MeOH (200 mL), the system was placed under nitrogen and 10% Pd/C (681 mg, 6.4 mmol, 0.1 equiv) was carefully added. The resulting mixture was stirred under a H2 atmosphere (1 atm) until disappearance of the starting material as monitored by LC-MS analysis. Hydrogen was removed followed by filtration through a celite plug and washing of the solids with MeOH (4×75 mL). The filtrate was concentrated and the residue was purified via flash chromatography on a 120 g silica gel column (gradient elution 0 to 50% ethyl acetate in hexanes) to yield (3aR,6aR)-2,2-dimethyldihydro-3aH-cyclopenta[d][1,3]dioxol-4(5H)-one (1-2) as a white fluffy solid and (3aS,4S,6aR)-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (1-3) as a colorless oil. 1H NMR (1-2) (500 MHz, CDCl3): δ 4.84 (t, J=4.8 Hz, 1H); 4.19 (d, J=5.2 Hz, 1H); 2.65-2.53 (m, 1H); 2.33-2.23 (m, 2H); 2.11-2.01 (m, 1H); 1.43 (s, 3H); 1.38-1.31 (m, 3 II). 1H NMR (1-3) (400 MHz, CDCl3): δ 4.61 (t, J=5.3 Hz, 1H); 4.40 (t, J=5.6 Hz, 1H); 3.88-3.77 (m, 1H); 2.43 (d, J=9.9 Hz, 1H); 1.93-1.75 (m, 2H); 1.70-1.55 (m, 1H); 1.49 (s, 3H); 1.47-1.35 (m, 1H); 1.34 (s, 3H). Hydrogen was removed followed by filtration through a celite plug washing of the solids with MeOH (4×75 mL) The filtrate was concentrated the residue was purified via flash chromatography on a 120 g silica gel column (gradient elution 0 to 50% ethyl acetate in hexanes)

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

Procedure: (3 aR,6aR)-2,2-dimethyldihydro-3 aH-cyclopenta[d][1,3]dioxol-4(5H)-one (1-2) (2.75 g, 17.6 mmol, 1 equiv) was dissolved in methanol (166 mL) and sodium borohydride (1.0 g, 26.4 mmol, 1.5 equiv) was added portion wise at 0° C. Upon disappearance of the starting material as monitored by LC-MS analysis, water was added and the mixture was concentrated. The aqueous phase was extracted with DCM (3×100 mL), the combined organics were dried (Na2SO4), and the solvent was removed to afford (3AS,4S,6aR)-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (1-3) as a colorless oil that did not require further purification. was added the mixture was concentrated The aqueous phase was extracted with DCM (3×100 mL) the combined organics were dried (Na2SO4) the solvent was removed

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

Procedure: (3aS,4S,6aR)-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (1-1) (10 g, 64.0 mmol, 1 equiv) was dissolved in MeOH (200 mL), the system was placed under nitrogen and 10% Pd/C (681 mg, 6.4 mmol, 0.1 equiv) was carefully added. The resulting mixture was stirred under a H2 atmosphere (1 atm) until disappearance of the starting material as monitored by LC-MS analysis. Hydrogen was removed followed by filtration through a celite plug and washing of the solids with MeOH (4×75 mL). The filtrate was concentrated and the residue was purified via flash chromatography on a 120 g silica gel column (gradient elution 0 to 50% ethyl acetate in hexanes) to yield (3aR,6aR)-2,2-dimethyldihydro-3aH-cyclopenta[d][1,3]dioxol-4(5H)-one (1-2) as a white fluffy solid and (3aS,4S,6aR)-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (1-3) as a colorless oil. 1H NMR (1-2) (500 MHz, CDCl3): δ 4.84 (t, J=4.8 Hz, 1H); 4.19 (d, J=5.2 Hz, 1H); 2.65-2.53 (m, 1H); 2.33-2.23 (m, 2H); 2.11-2.01 (m, 1H); 1.43 (s, 3H); 1.38-1.31 (m, 3 II). 1H NMR (1-3) (400 MHz, CDCl3): δ 4.61 (t, J=5.3 Hz, 1H); 4.40 (t, J=5.6 Hz, 1H); 3.88-3.77 (m, 1H); 2.43 (d, J=9.9 Hz, 1H); 1.93-1.75 (m, 2H); 1.70-1.55 (m, 1H); 1.49 (s, 3H); 1.47-1.35 (m, 1H); 1.34 (s, 3H). Hydrogen was removed followed by filtration through a celite plug washing of the solids with MeOH (4×75 mL) The filtrate was concentrated the residue was purified via flash chromatography on a 120 g silica gel column (gradient elution 0 to 50% ethyl acetate in hexanes)