| 摘要 |
1500229 Alkyl indans HEXACHIMIE SA 26 Aug 1976 [26 Sept 1975] 35449/76 Heading C5E [Also in Division C2] 2-Alkyl indans of Formula (IV) in which R is C 1 -C 5 alkyl or C 3 -C 7 cycloalkyl are prepared by (a) condensing an aromatic ketone of Formula (I) with formaldehyde (or a polycondensed form of formaldehyde liberating formaldehyde under the conditions) in a basic medium and in a polar organic solvent to obtain a ketol of Formula (II); (b) cyclizing the ketol in a strong acid medium to obtain an indanone of Formula (III) and (c) reducing the indanone to give the desired 2- alkyl indan. The reduction of stage (c) may be Clemmenson, Wolff-Kishner or catalytic hydrogenation. Examples describe the preparation of 2- ethyl- and 2-isopropyl-indans. |
