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To a stirred suspension of Zn (0.50 g, 7.59 mmol) in THF (10 mL) was added TiCl4 (0.42 mL, 3.79 mmol) dropwise. The mixture was refluxed under nitrogen for 2.5 h. Cooled to room temperature, a solution of 96 (0.245 g, 0.95 mmol) and 3,3,5,5-tetramethylcyclohexanone (0.45 g, 2.85 mmol) in THF (15 mL) was added at once. The reaction mixture was refluxed for another 2.5 h. Cooled to room temperature, the reaction was quenched with 10% K2CO3 (20 mL). The quenched reaction mixture was filtered through a pad of Celite and the pad was washed with EtOAc (100 mL). The filtrate was transferred to a separatory funnel, the layers were separated and the aqueous phase was extracted with EtOAc (50 mL). The organic extracts were combined, washed with brine and dried (Na2SO4). Concentration yielded a pale brown oil which was further purified by chromatography on a silica gel column eluted with a gradient from hexanes to 45% EtOAc:hexanes to give a a light yellow solid, Crystallization from 7:1 hexanes:EtOAc yielded 97 as colorless needles (0.15 g, 42%). mp 154-155° C. 1H NMR (400 MHz, CD3OD): δ 0.91 (s, 6H), 0.92 (s, 6H), 1.28 (s, 2H), 1.96 (s, 2H), 1.98 (s, 2H), 3.80-3.90 (m, 2H), 4.00-4.10 (m, 2H), 6.67 (d, J=8.5 Hz, 2H), 6.84 (d, J=8.6 Hz, 2H), 6.94 (d, J=8.6 Hz, 2H), 7.03 (d, J=8.6 Hz, 2H). LRMS (ESI): m/z 381 (M+H)+, 379 (M−H)−. The sample was silated prior to EI analysis. HRMS (EI) Calcd for C31H48O3Si2: 524.3142 (M+.). Found: 524.3128.

1. temperatureThe mixture was refluxed under nitrogen for 2.5 h
2. temperatureThe reaction mixture was refluxed for another 2.5 h
3. temperatureCooled to room temperature
4. customthe reaction was quenched with 10% K2CO3 (20 mL)
5. customThe quenched reaction mixture
6. filtrationwas filtered through a pad of Celite
7. washthe pad was washed with EtOAc (100 mL)
8. customThe filtrate was transferred to a separatory funnel
9. customthe layers were separated
10. extractionthe aqueous phase was extracted with EtOAc (50 mL)
11. washwashed with brine
12. dry with materialdried (Na2SO4)
13. concentrationConcentration
14. customyielded a pale brown oil which
15. customwas further purified by chromatography on a silica gel column
16. washeluted with a gradient from hexanes to 45% EtOAc
17. customhexanes to give a
18. customa light yellow solid, Crystallization from 7:1 hexanes