[CH2:1]([C:3]1[C:4](=[O:10])[CH2:5][CH2:6][C:7]=1[CH:8]=O)[CH3:2].CO[CH2:13][CH2:14][O:15]C>>[O:15]=[C:14]([CH2:2][CH2:1][CH2:3][CH2:7][CH3:6])/[CH:13]=[CH:8]/[C:7]1[CH2:6][CH2:5][C:4](=[O:10])[C:3]=1[CH2:1][CH3:2]1.7 g (0.035 mole) of a 50% NaH dispersion is transferred into a dry 500 ml 3-neck flask equipped with an addition funnel, overhead stirrer and septum. The NaH was covered with 175 ml of DME and a solution of 10.1 g (0.045 mole) dimethyl (2-oxoheptyl) phosphonate in 12 ml of DME is added dropwise over a 10 minute period. The mixture is stirred for 1 hour at room temperature to form the sodium salt of the phosphonate. A solution of the crude aldehyde 5 supra [from oxidation of 7.0 g (0.05 mole) of the vinyl compound 4] in 25 ml of DME was added over a twenty-minute period, and the mixture was stirred an additional two hours. The reaction was terminated by the addition of 2.5 ml glacial acetic acid followed by 175 ml water. The reaction mixture was extracted with CHCl3, and the combined organic extracts washed with water and dried over sodium sulfate. The CHCl3 was removed under reduced pressure to yield 12.6 g of crude product. This material was chromatographed over silicic acid using ethyl acetate-cyclohexane for elution to give 6.7 g (80%) of a yellow liquid Ic. The spectral characteristics of this compound were similar to Ia and Ib with the ##STR6## group evident in the nmr spectrum, --(CH2)4CH3 at δ0.9.
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