Triethylamine → 6,6-Dimethoxyhex-1-ene

The crude product containing compound 5 was taken up in 30 mL of MeOH, and camphorsulfonic acid (596 mg, 2.5 mmol) and trimethyl orthoformate (5.46 mL, 50 mmol) were added. The mixture was heated at reflux for 3 h, then allowed to stand at room temperature overnight. The acid was neutralized by the addition of 0.70 mL of triethylamine, and most of the solvent was removed by distillation. The residue was partitioned between water and hexane, the hexane layer was dried over anhydrous Na2SO4, and the solution was filtered through a 3 in column of silica gel, eluting with additional hexane. The solvent was removed by distillation to leave 5.0 g of the product, compound 6, as a colorless liquid. 1H NMR (CDCl3) δ 1.39-1.49 (m, 2), 1.58-1.65 (m, 2), 2.03-2.11 (m, 2), 3.31 (s, 6, CH(OCH3)2), 4.37 (t, 1, J=5.7CH(OCH3)2), 4.93-5.05 (m, 2, CH═CH2), 5.80 (dddd, 1, J=6.6, 6.6, 10.3, 16.9, CH═CH2); 13C NMR (CDCl3) δ 23.79, 31.83, 33.42, 52.49, 104.33, 114.64, 138.38.

1. temperatureThe mixture was heated
2. temperatureat reflux for 3 h
3. custommost of the solvent was removed by distillation
4. customThe residue was partitioned between water and hexane
5. dry with materialthe hexane layer was dried over anhydrous Na2SO4
6. filtrationthe solution was filtered through a 3 in column of silica gel
7. washeluting with additional hexane
8. customThe solvent was removed by distillation

ORD record

ord-daf25ace109e4dc19123c9a122990825

Source dataset

uspto-grants-2001_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06218519B1