Synthesis and absolute configuration of hormone α1

An important biological event in phytopathogens of the genus Phytophthora is sexual reproduction, which is conducted by two mating types, A1 and A2. A factor known as hormone α1 is secreted by the A1 mating type and induces the formation of sexual spores (oospores) in the A2 mating type. Here we describe the asymmetric synthesis and assignment of the absolute configuration of hormone α1 by oospore-inducing assays of the synthesized isomers.