PURPOSE: To obtain the titled compound useful as an intermediate for ascorbic acid, etc., on an industrial scale at a low cost, by reacting L-sorbose under the addition of acetone having low water-content in the presence of a ketalization catalyst while distilling out produced water together with acetone.
CONSTITUTION: The objective compound is produced by reacting L-sorbose with acetone in the presence of a ketalization catalyst (e.g. concentrated sulfuric acid, etc.). The reaction is carried out by charging dehydrated acetone having a water-content of ≤100ppm, L-sorbose and concentrated sulfuric acid into a reactor, reacting the components in a hot bath of 45°C under reduced pressure while adding dehydrated acetone having a water-content of ≤100ppm to the system and distilling out acetone containing water produced by the reaction. The reaction product is neutralized with an aqueous solution of sodium hydroxide, acetone is distilled out, the obtained aqueous solution is extracted with benzene and benzene is distilled out to obtain the objective compound.
SAWADA HITOSHI
YOKOYAMA MASAO
| JPS6072895A | 1985-04-24 | |||
| JPH0629198A | 1994-02-04 |