Forster重氮化合物合成反应

重氮化合物是有机合成中非常重要的一类中间体，一般指脂肪族重氮化合物，大多具爆炸性。重氮化合物中的重氮基有四个共振式，中间氮原子带有部分正电荷，两端的碳和氮原子带负电荷。α-重氮酮和α-重氮酯中的负电荷可以离域到羰基上去，因此比较稳定。

肟与次氯酸钠和氨水作用得到重氮化合物的反应被称为Forster反应。此反应由Forster在1915年首先报道，他利用α-肟基酮和氯胺反应得到了重氮酮。

反应机理

反应实例

2-Diazo-4,4-dimethylcholest-5-en-3-one (5). 4N aq NaOH (125 mL) and 40 mL conc NH4OH were added to 10 g of 2-oximino-4,4-dimethylcholest-5-en-3-one (4, 10 g) in a minimum amount of THF, followed by slow addition of 100 mL of aq 5.25% NaOCl (Clorox) at 10 C over 1 h with vigorous stirring. Addition of water produced 8.7 g of a yellow solid. Chromatography (alumina, CHCl3, MeOH) and air drying afforded 6.74 g of 5, mp 129–130 C. Additional 0.97 g fromthe filtrate, total yield of 5 was 78%.

相关文献

1 Forster MCJ J Chem Soc 1915 107 260

2 Meinwald J J Am Chem Soc 1959 81 4751

3 Kirmse M Angew Chem 1957 69 106

4 Rundel W Angew Chem 1962 74 469

5 Hassner A Tet Lett 1962 3 759

6 Cava MP Steroids 1964 4 1789

7 Brewer M Org Lett 2007 9 1789

8 Davies HML Org Lett 2007 9 2625

编译自：Organic Syntheses Based On Name Reactions, 3RdEd, A. Hassner, Page 161.