Clerodane diterpenoids and an ursane triterpenoid from <i>Salvia haenkei</i>. Computer-assisted structural elucidation

Five <i>ent</i>-clerodane diterpenoids, four new, and a new ursane triterpenoid have been isolated from <i>Salvia haenkei</i> collected in Bolivia. The structures of two <i>ent</i>-clerodanes, <i>ent</i>-(4<i>S</i>,5<i>R</i>)-7α-acetoxy-15,16-epoxy-10-oxo-9,10-secocleroda-1,8,13(16),14-tetraene-17,12<i>S</i>;18,19-diolide <b>1</b> (salvianduline B) and <i>ent</i>-(5<i>R</i>,9<i>R</i>)-15,16-epoxy-10<i>S</i>-hydroxy-cleroda-3,7,13(16),14-tetraene-17,12<i>S</i>;18,19-diolide <b>2</b>, were elucidated from HMQC and HMBC data using an automatic structure elucidation computer program. The structures of the other clerodanes, <i>ent</i>-(5<i>R</i>,9<i>R</i>)-15,16-epoxy-10<i>S</i>-hydroxy-cleroda-3,13(16),14-triene-17,12<i>S</i>;18,19-diolide <b>6</b>, <i>ent</i>-(4<i>S</i>,5<i>R</i>,9<i>S</i>,10<i>R</i>)-15,16-epoxycleroda-1,13(16),14-triene-17,12<i>S</i>;18,19-diolide <b>7</b> and <i>ent</i>-(5<i>R</i>,9<i>R</i>,10<i>S</i>)-7<i>S</i>-acetoxy-15,16-epoxy-1<i>S</i>,2<i>S</i>,12ξ-trihydroxycleroda-3,13(16),14-trien-18,19-olide <b>8</b>, were derived in the usual manner from ¹H and ¹³C NMR data. The stereochemistry of <b>2</b> was confirmed by an X-ray crystal structure analysis. The triterpenoid is 3-oxours-12-ene-1β,11α-diol <b>9