A method for the synthesis of a compound of formula I as a mixture of enantiomers,
(wherein R
1
is H or an acid protective group and H
+
A
−
indicates an optional acid with which the compound of formula I may form an ammonium salt)
said method comprising; A) reacting a cyclohexyl aziridine with a dialkyl malonate, whereby to provide a trans-fused 3-alkylcarbonyl-octahydro-indol-2-one; B) decarbonylation at the 3-position, conversion of the ketone of the resulting trans-octahydro-indol-2-one to an optionally protected carboxylic acid group; and C) optionally removing any N-substitution if necessary.
一种合成式I化合物的方法,该化合物为对映体混合物,其中R1为H或酸保护基,H+A−表示该化合物可以形成
铵盐的可选酸。该方法包括:A)将环己基氮杂环与二烷基
丙二酸酯反应,从而提供反式螺环3-烷基酰基-八氢
吲哚-2-酮;B)在3位脱羰基化,将所得反式八氢
吲哚-2-酮的酮转化为可选的保护
羧酸基;C)必要时可选择性地去除任何N-取代基。