Photochemistry in porous materials, ii .1. photolysis of benzoin ethers in silicalite

Four benzoin ethers 1 (a: methyl-, b: ethyl-, c: isopropyl-, d: phenylether) were photolyzed inside the channel system of silicalite S-115, a novel type of zeolite. Products which could be separated from the zeolite framework in various relative yields were pinacol ethers (from a, b, c), benzil (a - d), benzaldehyde (a - d), benzoates (a - d), and phenol (d). While the former three types of products clearly arise from Norrish type I cleavage of the parent molecules, a mechanism involving the enolic form of the benzoin ethers is proposed in order to explain the formation of benzoates and phenol