An Insecure Role for Securin in Chromosome Segregation

A photochemical route for the synthesis of some benzopyronospiropyrans from 2-furyl-3cycloalkenyloxybenzopyrones involving H-abstraction is reported. How a methyl group on the furyl ring affects the product formation is also investigated. 1. Background Spiropyrans exhibit photochromism due to the photoequilibrium with their open chain analogues merocyanins – a property that makes them a material of choice in digital storage technology. [1-5] Some spiropyrans have been found to have antiphlogistic, spasmolytic, antidiabetic and antifeedant activities amongst others. [6-10] The methods available for the synthesis of spiropyrans include enamine eliminations, reductive/thermal cyclisations and [4+2] cycloadditions. [11-16] These methods being specific in nature for a particular spirocyclic compound, offer limited synthetic utility. In the past, we have investigated the use of photochemical methods for the synthesis of organic molecules like vinyl ethers, [17] pyranopyrones [18,19] etc. and in continuation of that work we published a preliminary report on photochemical synthesis of spiropyrans. [20] To extend and examine the scope of this methodology, in this communication, we report the synthesis of spiropyrans bearing dihydrofuryls and acylcyclopropanes. 2. Results The substrates 1 and 2 required for this study were obtained through the alkylation of 6-chloro-2-(2'-furyl)3-hydroxy-4-oxo-4H-1-benzopyrans [21]3 (R = H) and 4 (R = CH3) with an appropriate bromocycloalkene (R' Br). Scheme 1: Synthesis of 3-Cycloalkenyloxybenzopyrans. The irradiation of 1c in methanol with pyrex filtered light from a 125W Hg lamp produced two products 5c and 6c along with some 3. Published: 21 March 2007 Beilstein Journal of Organic Chemistry 2007, 3:14 doi:10.1186/1860-5397-3-14 Received: 9 February 2007 Accepted: 21 March 2007 This article is available from: http://bjoc.beilstein-journals.org/content/3/1/14 © 2007 Gupta et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.