海人草有効成分ならびに関連化合物の研究 第58報
L-α-Allokainic Acidの合成 その3
1958 年 78 巻 8 号 p. 867-872
詳細
1958 年 78 巻 8 号 p. 867-872
Knoevenagel condensation of ethyl 4-cyanocrotonate (VI) and ethoxyacetone (LVI) with β-alanine as a catalyst, afforded ethyl 4-cyano-5-methyl-6-ethoxy-trans-2, 4-hexadienoate (LVII). Addition of diethyl malonate to (LVII) in the presence of sodium ethoxide gave diethyl (1-ethoxycarbonylmethyl-2-cyano-3-methyl-4-ethoxy-2-butenyl) malonate (LX), which was submitted to high-pressure reduction to form ethyl 2-oxo-3-ethoxycarbonyl-5-(1-methyl-2-ethoxyethyl)-4-piperidineacetate (LXIII). Chlorination of (LXIII) followed by treatment with barium hydroxide formed the pyrrolidine compound (LXV), and substitution of its 1-methyl-2-ethoxyethyl group with isopropenyl finally afforded L-α-allokainic acid.
