Morales-Rios, MS; Rivera-Becerril, E; Lopez-Camacho, PY ; Perez-Rojas, NA ; Suarez-Castillo, OR, Preparation of O-Methyl Substituted 2-Oxofuro- and 2-Oxopyrrolidinoindolines by Reductive Lactonization of Oxindol-3-ylacetic Acids, NATURAL PRODUCT COMMUNICATIONS. Año: 2012 Volume: 7 Issue: 11 Pages: 1445-1451.ISSN: 1934-578X
A practical procedure for the preparation of O-methyl substituted 3a,8-dialkyl-2-oxofuroindolines is described. Reductive lactonization of the corresponding oxindol-3-ylacetic acids provides a route for the formation of this class of compounds. Further transformation of 2-oxofuroindolines into 2-oxopyrrolidinoindolines, and then to pyrrolidinoindolines demonstrates their versatility as key intermediates in natural products synthesis. The results of single-crystal X-ray crystallographic analyses are given for five of the studied compounds.