Photoirradiation of [3.3]cyclophane-2,11-diones with a high-pressure Hg lamp in benzene provides the corresponding [2.2]cyclophanes in high yields along with [3.2]-cyclophane-2-ones. (C) 1998 Elsevier Science Ltd. All rights reserved.
SHINMYOZU, TERUO;HIRAI, YOSHIO;INAZU, TAKAHIKO, J. ORG. CHEM., 1986, 51, N 9, 1551-1555