N-bromobutanimide → (E)-6-(Bromomethylene)tetrahydro-2H-pyran-2-one

This compound was prepared according to the procedure set forth in Kraft et al, J. Am. Chem. Soc., 103, 5459-5466 (1981). A mixture of the 5-hexynoic acid of Part A (1.1 g, 9.8 mmol), KHCO3 (1.5 g, 15 mmol), N-bromosuccinimide (2.6 g, 15 mmol) and 0.4M aqueous tetrabutylammonium hydroxide (2 mL, 0.8 mmol) in CH2Cl2 (90 mL) was stirred at room temperature for 3.5 h. The mixture was washed with 5% Na2S2O3 and saturated NaCl. The organic phase was dried (MgSO4) and the solvent was removed in vacuo to give a residue weighing 1.8 g. The residue was purified by flash chromatography (silica gel, Aldrich catalog #22,719-6, 230-400 mesh). The column was eluted with CH2Cl2 and fractions having a spot with Rf =0.32 (CH2Cl2, Bakerflex IBF-2 silica TLC plates) were combined. The solvent was removed in vacuo to give 1.0 g (58% yield) of product as a colorless oil.

1. customThis compound was prepared
2. washThe mixture was washed with 5% Na2S2O3 and saturated NaCl
3. dry with materialThe organic phase was dried (MgSO4)
4. customthe solvent was removed in vacuo
5. customto give a residue
6. customThe residue was purified by flash chromatography (silica gel, Aldrich catalog #22,719-6, 230-400 mesh)
7. washThe column was eluted with CH2Cl2 and fractions
8. customThe solvent was removed in vacuo

ORDレコード

ord-c740cd479c624550bb540fbdee790919

出典データセット

uspto-grants-1993_05

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US05208244