Alkaline hydrolysis of nonpenolic α-carbonyl β-0-4 lignin dimers substituted on the leaving phenoxide ring: comparison with benzylic hydroxyl analogues

摘要

Foru α-carbonyl nonphenolic β-9-4 lignin models [2-(2-methoxy-3- or 4- substitutedphnoxy)-1-(3,4- dimentoxyphenyl)-ethan-1-one] were synthesized and the alkaline hydrolysis rates determined. The rates were then compared to rates for α-hydroxyl analogues run earlier. The unsubstituted ketone hydrolzed slightly slower, about 30/100, then the alcohol analogue. The 4'-CHO ketone hydrolyzed much faster than the unsubstituted ketone and had essentially the same hydrolysis rate as the alsohol analogue. No definitive mechanistic conclusions could be made about the alkaline hydrolysis reaction of the ketones.