Stereoselective Synthesis of 4-Alkyloxy-2-/β-Bromopodophyllotoxin Derivatives as Insecticidal Agents

摘要

Interesting insecticides: 4-Alkyloxy-2/β-bromopodophyllotoxin derivatives were readily prepared with excellent stereoselectivity due to intramolecular steric effects (see scheme). The ratio of two stereoisomers, 2/β-bromo-4-O-tetrahydropyranylpodophyllotoxin, could be well controlled by the reaction temperature.