Sodium hydride → 8-Benzylidene-1,4-dioxaspiro[4.5]decane

To a suspension of NaH (0.306 g, 12.8 mmol) in DMSO (10 mL), a solution of benzyl-triphenylphosphonium bromide (5.44 g, 12.8 mmol) in DMSO (30 mL) was slowly added at rt. The solution was stirred 30 min at rt and then further 30 min at 50° C. Upon the crude mixture turning into dark red color, a solution of 1,4-dioxaspiro[4.5]decan-8-one (2.0 g, 12.8 mmol) in DMSO (14 mL) was added. The solution was stirred at 50° C. for 16 h. The reaction mixture was quenched with water and the aqueous layer extracted with AcOEt (3×20 mL). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated to dryness to give a crude product, which was purified by column chromatography using a Teledyne ISCO apparatus, eluting with Cy/AcOEt (from 100:0 to 40:60) to afford the title compound (1.8 g, 61%) as a white solid. 1H NMR (CDCl3): δ 1.66-1.73 (m, 2H), 1.77-1.84 (m, 2H), 2.40-2.47 (m, 2H), 2.49-2.57 (m, 2H), 3.99 (s, 4H), 6.31 (s, 1H), 7.17-7.23 (m, 3H), 7.28-7.35 (m, 2H).

1. customfurther 30 min
2. customat 50° C
3. stirringThe solution was stirred at 50° C. for 16 h
4. customThe reaction mixture was quenched with water
5. extractionthe aqueous layer extracted with AcOEt (3×20 mL)
6. washThe combined organic layers were washed with brine
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated to dryness
10. customto give a crude product, which
11. customwas purified by column chromatography
12. washeluting with Cy/AcOEt (from 100:0 to 40:60)

ORD record

ord-dca35d5b89924464abf6c3e428816921

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09353075B2