반응 #2012047

반응 방정식

α-bromo-α-methyl-γ-butyrolactone

thioacetic acid S-(tetrahydro-pyran-4-yl)ester

KOH

acetyl chloride

→

desired product

수율 46.2%

3-Methyl-3-(tetrahydro-pyran-4-ylsulfanyl)-dihydrofuran-2-one

수율 46.2%

용매

2-propanol

—

2-proponal

반응 조건

후처리

1. 1
   workup.STIRRINGThe mixture was stirred 2 hours
2. 2
   기타the volatiles removed in vacuo
3. 3
   workup.ADDITIONThe residue was diluted with ether
4. 4
   여과filtered
5. 5
   기타Removal of the volatiles in vacuo
6. 6
   기타provided a residue which
7. 7
   기타was purified by silica gel chromatography
8. 8
   농축The product-rich fractions were concentrated in vacuo

실험 절차

To thioacetic acid S-(tetrahydro-pyran-4-yl)ester (4.25 g; 26.5 mmol) in 2-proponal (20 mL) was added KOH (36.4 mL of a 0.8 M solution in 2-propanol; 29.2 mmol). The mixture was stirred 30 minutes and α-bromo-α-methyl-γ-butyrolactone (3.00 mL; 26.5 mmol) was added dropwise. The mixture was stirred 2 hours, quenched with acetyl chloride (0.62 mL; 8.75 mmol) and the volatiles removed in vacuo. The residue was diluted with ether and filtered. Removal of the volatiles in vacuo provided a residue which was purified by silica gel chromatography using ethyl acetate and hexanes as the eluent. The product-rich fractions were concentrated in vacuo to provide 2.65 g of the desired product. 1H NMR (CDCl3) δ 4.45 (m, 1H), 4.29 (dt, 1H), 3.89 (m, 2H), 3.48 (dq, 2H), 3.20 (m, 1H), 2.33 (m, 1H), 2.21 (m, 1H), 1.95 (m, 1H), 1.88 (m, 1H), 1.86 (m, 2H), 1.65 (s, 3H).

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