| 摘要 |
<p>PURPOSE:To obtain the titled stable compound including a novel compound, in high yield, by using 3-O-alkyl or aralkyl-5,6-O-isopropylidene-L-ascorbic acid as a raw material, and eliminating its protective group under mild acidic conditions. CONSTITUTION:The compound of formula II obtained by the reaction of the compound of formulaIwith an alkyl halide or aralkyl halide of formula RX (R is lower alkyl or aralkyl; X is halogen) in the presence of an alkali (e.g. sodium bicarbonate) in a non-hydroxy-containing solvent (e.g. acetone, DMF, etc.), is used as a raw material, and is heated in hydrated acetic acid at 90- 100 deg.C for 15-45min to eliminate the 5,6-O-isopropylidene-protective group and to obtain the compound of formula III (the compounds wherein R is other than methyl or benzyl are novel compounds). The compound of formula III is hardly decomposed at 37 deg.C under neutral or basic conditions, and is nontoxic. It is suitable as an active component (vitamin C) for compounding to drug, cosmetics, agent for oral cavity application, etc.</p> |
