A CONCISE AND CONVENIENT SYNTHESIS OF DL-PROTO-QUERCITOL AND DL-GALA-QUERCITOL VIA ENE REACTION OF SINGLET OXYGEN COMBINED WITH [2-CYCLOADDITION TO CYCLOHEXADIENE(4])
E. Salamci et al., A CONCISE AND CONVENIENT SYNTHESIS OF DL-PROTO-QUERCITOL AND DL-GALA-QUERCITOL VIA ENE REACTION OF SINGLET OXYGEN COMBINED WITH [2-CYCLOADDITION TO CYCLOHEXADIENE(4]), Journal of organic chemistry, 62(8), 1997, pp. 2453-2457
Photooxygenation of 1,4-cyclohexadiene afforded hydroperoxy endoperoxi
des 3 and 4 in a ratio of 88:12. Reduction of 3 with LiAlH4 or thioure
a followed by acetylation of the hydroxyl group and KMnO4 oxidation of
the double bond gave proto-quercitol 10b. Application of the same rea
ction sequences to 4 resulted in the formation of gala-quercitol 14. Q
uercitols were easily obtained by ammonolysis of acetate derivatives i
n MeOH. The outcome of dihydroxylation reactions were supported by con
formational analysis.