1961 年 81 巻 7 号 p. 951-956
Reaction of DL-methionine ethyl ester to the active derivatives of α-lipoic acid (I), i.e. α-lipoic butylcarbonic anhydride (III), O-α-lipoyl phosphorodichloridate (IV), benzyl α-lipoate (V), and S-benzyl thio-α-lipoate (VI), and hydrolysis of the product with sodium hydroxide affords N-α-lipoyl-DL-methionine (VIII), which is also obtained by the reaction of 6, 8-dichloroöctanoyl chloride (IX) and DL-methionine ethyl ester with subsequent application of sodium sulfide.
As the mixed acid anhydride of (I), butyl- (III), isobutyl- (XI), octyl- (XII), and isoöctyl-carbonic anhydride (XIII) were prepared and their reaction with copper complex compound of L-lysine afforded N6-α-lipoyl-L-lysine (XIV). Reaction of 6, 8-dichloroöctanoic alkylcarbonic anhydride and copper complex compound of L-lysine gives N6-(6, 8-dichloroöctanoyl)-L-lysine (XVIII) which reacts with sodium sulfide to form (XIV).
α-Lipoic alkylcarbonic anhydride reacts with N2-acetyl-L-lysinamide (XXIII), obtained by catalytic reduction of N2-acetyl-N6-benzyloxycarbonyl-L-lysinamide (XXII), to form N2-acetyl-N6-α-lipoyl-L-lysinamide (XXIV).