At 0° C., 0.146 g (3.86 mmol) of sodium borohydride was added to a solution of 1.436 g (3.86 mmol) of CeCl3.7H2O and 3.67 mmol of methyl (E)-8-(2-{[tert-butyl(dimethyl)silyl]oxy}phenyl)-6-oxo-7-octenoate from Ex. XIIc in 30 ml of methanol. The mixture was stirred at 0° C. and the progress of the reaction was monitored by thin-layer chromatography. Saturated NH4Cl solution was added, the mixture was extracted with ethyl acetate and the combined organic phases were dried over Na2SO4. The product was purified chromatographically (silica gel, cyclohexane/EA 10:2). This gave 1.38 g (91.5%) of a colorless liquid.
