2-Methylalkanoic acids resolved by esterification catalysed by lipase from Candida rugosa: Alcohol chain length and enantioselectivity
摘要:
Enantiomerically pure (R)-2-methyldecanoic acid and (S)-2-methyl-1-decanol were prepared in a multi gram scale by esterification reactions catalysed by lipase from Candida rugosa. The enantiomeric ratios (E-values) were determined as a function of the chain length of the alcohol used as the complementary substrate in cyclohexane. In the resolution of 2-methyldecanoic acid the highest value (E = 37 +/- 5) was obtained, when either 1-hexanol, 1-heptanol or 1-octanol were used. In contrast, when resolving 2-methyloctanoic acid, the E-values increased continually with increasing chain length of the alcohol used. 1-Hexadecanol gave the highest value: E > 100. The E-values were determined from the enantiomeric excess (ee) of the product, at, a conversion below 0.4. After two consecutive esterification reactions enantiomerically pure (R)-2-methyldecanoic acid, > 99.8% ee, and after subsequent reduction of the ester produced, (S)-2-methyl-1-decanol, 96.7% ee, were obtained.
Synthesis of a tetraamido macrocycle ligand from a novel diamidodiol
申请人:The Clorox Company
公开号:US06384279B1
公开(公告)日:2002-05-07
A new composition of matter for a diamidodiol and a method for preparing the diamidodiol. The exemplary diamidodiol has the formula C15H30N2O4 and is prepared by reacting a first quantity of 2-amino-2-methyl-1-propanol with a second quantity of a di-substituted malonyl dichloride (i.e., diethylmalonyl dichloride), preferably in ethyl acetate as solvent. A tetraamido macrocycle is prepared from the diamidodiol in two steps by oxidizing the diamidodiol to form a diacid followed by coupling using a known procedure of the diacid with an aryl diamine (e.g., 1,2-diaminobenzene) to yield the tetraamido macrocycle.
Total synthesis of verticipyrone, a novel NADH-fumarate reductase inhibitor, has been accomplished by a convergent approach using novel "Reverse Julia olefination" method. During total synthetic studies, we also prepared and evaluated several synthetic verticipyrone analogues, some of which exhibited more potent antiparasitic activity than the natural verticipyrone.
Schulte et al., Hoppe-Seyler's Zeitschrift fur Physiologische Chemie, 1951, vol. 288, p. 69,71