Pyridine → (3aR,4S,6aR)-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-yl methyl carbonate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

(3aS,4S,6aR)-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (2-1) (9.76 g, 62.5 mmol, 1.0 equiv) was dissolved in DCM (200 mL). Pyridine (7.58 mL, 94.0 mmol, 1.5 equiv) was added and the mixture stirred at 0° C. After 1 hour DMAP (3.05 g, 25.0 mmol, 0.4 equiv) was added followed by methyl chloroformate (19.4 mL, 250 mmol, 4 equiv). The resulting mixture was stirred overnight, and the temperature was allowed to slowly increase to room temperature. The reaction was partitioned between DCM and water, and the organic layer was separated and washed with water, dried (MgSO4), and concentrated to yield desired (3aR,4S,6aR)-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-yl methyl carbonate (2-2) as a colorless oil. 1H NMR (500 MHz, CDCl3): δ 6.10 (d, J=5.9 Hz, 1H); 5.91 (d, J=5.9 Hz, 1H); 5.30 (d, J=5.4 Hz, 1H); 5.03 (d, J=5.7 Hz, 1H); 4.92 (t, J=5.5 Hz, 1H); 3.83 (s, 3H); 1.40 (s, 3H); 1.38 (s, 3H).

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