2-Methyl-2-butene → (S)-4-acetoxypent-2-ynoic acid

To a solution of 9 (133 mg, 0.949 mmol) and 2-methyl-2-butene (1.20 mL, 14.2 mmol) in tBuOH (1.9 mL) was added the mixture of NaClO2 (257 mg, 2.84 mmol) and NaH2PO4 (393 mg, 2.84 mmol) in H2O (1.9 mL) at 23° C. The resulting mixture was stirred for 20 min at the same temperature and quenched by 1 N aqueous HCl (3 mL) at 0° C. The mixture was poured into a separatory funnel and diluted with EtOAc (3 mL). The layers were separated and the aqueous layer was extracted with EtOAc (3×4 mL). The combined organic layers were dried over Na2SO4, filtered, and concentrated in vacuo. Purification of the residue via flash chromatography (silica gel 15 mL; 50→100% EtOAc in hexanes containing 1.0% acetic acid) afforded acid 10 (149 mg, quantitative yield) as a pale yellow oil.

1. customquenched by 1 N aqueous HCl (3 mL) at 0° C
2. additionThe mixture was poured into a separatory funnel
3. additiondiluted with EtOAc (3 mL)
4. customThe layers were separated
5. extractionthe aqueous layer was extracted with EtOAc (3×4 mL)
6. dry with materialThe combined organic layers were dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customPurification of the residue via flash chromatography (silica gel 15 mL; 50→100% EtOAc in hexanes containing 1.0% acetic acid)

ORD record

ord-388c0eb8c23f4f9eacdd01bceaa2f18c

Source dataset

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08309599B2