[O:1]1[C:5]2([CH2:10][CH2:9][CH:8]([CH2:11][OH:12])[CH2:7][CH2:6]2)OCC1.[H-].[Na+].[CH2:15](Br)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.[OH-].[Na+]>CN(C=O)C>[CH2:15]([O:12][CH2:11][CH:8]1[CH2:7][CH2:6][C:5](=[O:1])[CH2:10][CH2:9]1)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1
1,4-dioxaspiro[4.5]decan-8-ylmethanol (1.33 g, 7.72 mmol) was dissolved in DMF (14 mL) and then cooled to 0° C. To the solution was added NaH (0.402 g, 10.04 mmol) in portions and the mixture agitated at 10° C. for 1 h and then benzyl bromide (1.194 mL, 10.04 mmol) was added and the mixture agitated over 72 h. The reaction mixture was quenched with water and extracted with ether and the combined organic extracts dried (MgSO4), filtered and concentrated in vacuo and the crude product 8-((benzyloxy)methyl)-1,4-dioxaspiro[4.5]decane dissolved in acetonitrile (35 mL) and water (25 mL) and treated with 3N HCl (13 mL) and agitated at room temperature for 20 min upon which LCMS indicated desired product. The reaction mixture was quenched with 40 mmol aqueous NaOH and then extracted with EtOAc (200 mL) and the organic layer was washed with water and dried (MgSO4), filtered and concentrated in vacuo and the residue purified by flash chromatography (0-50% EtOAc/heptane) to afford 1.23 g of the desired product as a colorless syrup (73%). LCMS (m/z): 329.2 (MH+), 1.33 min.
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