7 (+)-ノルカンファーを用いる天然物の立体制御合成(口頭発表の部)

抄録

Stereo- and enantiocontrolled syntheses of a variety of natural products have been accomplished using optically pure (+)-norcamphor 1 as a common starting material. Sesquiterpenes (-)β-santalene 2 and (+)-epi-β-santalene 3 are synthesized formally without destroying the bicyclo[2.2.1]heptane framework of the chiral starting material 1. (-)-Semburin 4, a monoterpene from Swertia japonica, (+)-N-benzoylmeroquinene aldehyde 5, (-)-antirhine 6, and (+)-isocorynantheol 7, which are related to the Corynanthe type indole alkaloids, and (-)-kainic acid 8, a marine anthelmintic α-amino acid, are prepared through the oxabicyclo[3.2.1]octanone intermediate 19, obtained from (+)-norcamphor 1 by Baeyer-Villiger oxidation, by employing the formation and the cleavage of α-diketone monothioketal intermediates as key steps. Finally, a new chiral synthon 47 having the bicyclo[3.2.1]octenone framework has been prepared in both enantiomeric forms from (+)-norcamphor 1. Utilizing the new chiral synthon (+)-juvabione 9 and (+)-epijuvabione 10, both possessing juvenile hormone activity, are synthesized in stereo- and enantiocontrolled ways.