43 g of the product from 1d were dissolved in 300 ml of diethyl ether. A solution of 3.1 g of lithium borohydride in 300 ml of diethyl ether was added dropwise thereto. The mixture was stirred for 6 h and the reaction was stopped by cautious addition of 300 ml of a saturated potassium bicarbonate solution. The phases were separated and the organic phase was washed with 250 ml of a saturated sodium chloride solution. The organic phase was dried with sodium sulfate, and the solvent was removed in vacuo. The residue was chromatographed on silica gel.
