Effective combination of two-directional synthesis and rhenium(VII) chemistry: Total synthesis of meso polyether teurilene

The efficient total synthesis of the cytotoxic meso polyether teurilene (1), rarely occurring in nature, has been achieved through the effective combination of the concept of two-directional synthesis and the rapidly progressing rhenium(VII) chemistry. In the key rhenium(VII)-promoted syn oxidative cyclization reaction of the two-directional substrate 3, trans-syn diastereoselectivity (steric control) has been observed in contrast to our previous observation of cis-syn diastereoselectivities (chelation control) for bishomoallylic tertiary alcohols possessing the neighboring tetrahydrofuran (THF) ring. This synthesis in only 10 steps from commercially available methyl tiglate is significantly shorter than the previous one requiring 25 steps as reported by Shirahama et al.