Research Article

Catalytic Synthesis of Pyrano- and Furoquinolines Using Nano Silica Chromic Acid at Room Temperature

Table 1

Synthesis of pyrano- and furoquinolines using nano silica chromic acid (nano-SCA) catalyst in THF as solvent and at room temperature.

EntryProduct 4Product 5Time (min) aYield (%) bProduct ratio (trans : cis)
4 : 5

1693763.tab.001a693763.tab.001b558985 : 15

2693763.tab.001c693763.tab.001d709380 : 20

3693763.tab.001e693763.tab.001f959190 : 10

4693763.tab.001g693763.tab.001h659490 : 10

5693763.tab.001i693763.tab.001j709085 : 15

6693763.tab.001k693763.tab.001l8691.587 : 13

7693763.tab.001m693763.tab.001n8986.582 : 18

8693763.tab.001o693763.tab.001p1008879 : 21

9693763.tab.001q693763.tab.001r12087.578 : 22

Isolated yields. bIsomers were separated by column chromatography. bRatio of the product was determined from the crude 1H NMR spectra.