| 摘要 |
<p>PURPOSE:To obtain the titled nontoxic compound useful as an ameliorant of cerebral function and cardiovascular agent, etc., in high yield and a short process, by reacting a griseolic acid derivative which is a starting raw material with an alkylating agent and heating the formed compound. CONSTITUTION:A compound expressed by formula I (R<1> is H or protecting group of OH; R2 is H or OH which can be protected; R3 and R4 are H or protecting group of COOH; R5 and R6 are H or together form single bond) is first reacted with an alkylating or aralkylating agent expressed by the formula R7-X (R7 is lower alkyl or aralkyl; X is halogen, arylsulfonyloxy, etc.) normally in an inert solvent to give a compound, which is then heated in a solvent. The protecting groups are, as necessary, removed to give the aimed compound expressed by formula II. The above-mentioned heat treatment is preferably carried out by a method for distilling away the solvent from the reaction mixture of the compound expressed by formula I with the compound expressed by the formula R7-X, dissolving the resultant residue in a buffer solution at 4-12pH and heating the resultant solution, etc.</p> |
