| 摘要 |
<p>PURPOSE:To prepare the titled compound useful as an intermediate of pharmaceuticals having hypotensive activity, or plant-growth retarding agent, etc., by reacting cyanhydrin with an aliphatic ester, and treating the resulting compound with hydrogen halide. CONSTITUTION:An OH-protected cyanhydrin is made to react with an aliphatic ester in the presence of a base to obtain the compound of formula I (R is OH- protecting group; R<1> and R<2> are H, alkyl, aryl, aralkyl or together form polymethylene; R<3> is H or lower alkyl; R<4> is lower alkyl), e.g. (Z)-3-amino-4-(1-ethoxyethoxy)-2-pentenoic acid t-butyl ester. The objective compound of formula II, e.g. 4-amino-5-methyl-2(5H)-furanone can be produced by treating the compound of formula I with hydrogen halide in the absence of solvent or in an aprotic solvent at -80-+100 deg.C.</p> |
