反应详情

温度

5 °C

A suspension of n-heptyltriphenylphosphonium bromide (25.00 g, 0.057 mole), in dry, deaerated tetrahydrofuran (150 ml) was vigorously stirred at 5° C. under nitrogen and n-butyl lithium, 1.55 molar in hexane (46.6 ml, 0.073 mole, 1.3 equivalents), added dropwise. The reaction was stirred for 20 mins at 5° C., then treated dropwise with a suspension of sodium salicylaldehyde [prepared from salicylaldehyde (6.33 g, 0.052 moles) and one molar equivalent of sodium hydride in dry, deaerated THF (150 ml) under nitrogen] at 10° C. After stirring at 10° C. for 1 h, the reaction was poured into water (500 ml), acidified with dilute hydrochloric acid and extracted twice with diethyl ether. The combined organic extracts were washed with water (twice) and dried, (MgSO4). Evaporation of the solvent in vacuo yielded a pale yellow oil, which was purified by column chromatography using silica gel, eluting with dichloromethane/hexane [1:1] to give 6.14 g (58 %) of the single E isomer as a pale yellow oil.

1. customin dry
2. stirringThe reaction was stirred for 20 mins at 5° C.
3. stirringAfter stirring at 10° C. for 1 h
4. extractionextracted twice with diethyl ether
5. washThe combined organic extracts were washed with water (twice) and
6. customdried
7. customEvaporation of the solvent in vacuo
8. customyielded a pale yellow oil, which
9. customwas purified by column chromatography
10. washeluting with dichloromethane/hexane [1:1]
11. customto give 6.14 g (58 %) of the single E isomer as a pale yellow oil