Synthesis of (4R)-(+)-tert-Butyldimethylsiloxy-2-cyclopenten-1-one from (4R)-(+)-Hydroxy-2-cyclopenten-1-one -- DMAP as Catalyst.

1. A solution of (4R)-(+)-hydroxy-2-cyclopenten-1-one (7.7 g, 78 mmol), DMAP (0.96 g, 7.8 mmol) and triethylamine (20 g, 200 mmol), in dry dichloromethane (150 mL) is prepared, under nitrogen, and cooled with an ice-water bath.
2. A solution of tert-butyldimethylsilylchloride (14.2 g, 94 mmol) in dry dichloromethane (50 mL) is added over 10 min.  The ice-water bath is removed, and the reaction mixture is stirred at room temperature for 3 h.
3. Water (100 mL) is added, the organic layer separated and the aqueous phase extracted with dichloromethane (3 x 50 mL).  The combined organic solutions are dried over anhydrous magnesium sulfate, filtered and concentrated under vacuum.  The residue is passed down a short silica column (eluent 5% ethyl acetate in petroleum ether, b.p. 35-60°C).  Appropriate fractions are combined, evaporated and the resulting oil distilled in a short path distillation apparatus (b.p. 60°C at 0.1 mm) to give a colorless oil (13.2 g).  Crystallization of this material from pentane gave the product (10.6 g, 64%) as colorless needles.