Stereoselective epoxidation of 2-arylidene-1-indanones and 2-arylidene-1-benzosuberones
摘要:
Oxidation of the (E) and (Z) isomers of 2-arylidene-1-indanones (1) and 2-arylidene-1-benzosuberones (4) by alkaline hydrogen peroxide (method i) afforded the spiroepoxides trans-2a-g and trans-5a-g from both isomers as sole products in high yields. On the other hand, dimethyldioxirane epoxidation (method ii) of the (E) isomers 1a-g and 4a-g gave the corresponding trans spiroepoxides in good yields, whereas the (Z) isomers 1a, c, e and 4a, c, e led to the cis spiroepoxides in moderate yields. Dimethyldioxirane oxidation (method ii) of (Z)-1c and (Z)-4c, e gave diones 3c and 6c, e as by-products as well. Epoxidation of(Z)-1a, c, e and (Z)-4a, c, e by m-chloroperoxybenzoic acid (method iii) resulted in ca. 6:1 mixtures of cis-2a, c, e and trans-2a, c, e or cis-5a, c, e and trans-5a, c, e spiroepoxides.
One-pot inter- and intramolecular Friedel–Crafts reactions in Baylis–Hillman chemistry: a novel facile synthesis of ( E )-2-arylideneindan-1-ones
作者:Deevi Basavaiah、Ravi Mallikarjuna Reddy
DOI:10.1016/s0040-4039(01)00354-9
日期:2001.4
A simple one-pot stereoselective transformation of tert-butyl 3-aryl-3-hydroxy-2-methylenepropanoates, the Baylis–Hillman adducts obtained from t-butyl acrylate, into (E)-2-arylideneindan-1-ones involving one inter- and one intramolecular Friedel–Crafts reaction is described.