(9). To the allene 3 (260 mg of 94% pure material, 3.9 mmol, neat) was added 9-BBN (7.8 mL of 0.5 M solution in THF, 3.9 mmol). After stirring at 35" C for 2 h, the mixture was cooled to 25" C, and a solution of 2-acetoxy-5-azidopentanal (8) 22 (650 mg, 3.5 mmol) in THF (1 mL) was added slowly. After 2 h, 4 N sodium hydroxide (10 drops) was added, and stirring was continued for another 2 h. A small aliquot (ca. 0.2 mL) was removed, and the solvent ...
