| 摘要 |
<p>Improved method for H3C - = CH - CH2X (I) X = Hal, pref. Cl. Intermediate for methyl heptenone and hence for citral, citronellol, and vitamin A. To isoprene (1215 g.) and III (X = Cl; 100 g.), a mixture (2805 g.) of 32% HCl Aq (2550 g.) and 95% H2SO4 (255 g.) was added (30 mins.) at 30 deg., kept. 1 hr. at 30 deg., cooled at 20 deg., sepd., and the organic phase analysed, as follows:- Unreacted II 29.5% III 6.8% I 57% Overall yields of I and III were 84.6 and 1.2% resp. In absence of III, overall prodn. of I and III was 75.6 and 8.8% resp.</p> |
