11 エン反応を基盤とする多連続不斉中心の立体化学制御(口頭発表の部)  [in Japanese] 11 ENE APPROACHES TO STEREOCONTROL OVER CONTIGUOUS CHIRAL CENTERS  [in Japanese]

New approaches to stereocontrol over contiguous chiral centers are described which rely on the intramolecular ene reactions. (1) Acetylene ene-cyclizations proceed with high level (>90%) of trans diastereofacial control even over the quaternary centers. (2) The olefin ene-cyclizations involving Z-ene component have been found to proceed with high level (97%) of stereocontrol over three contiguous chiral centers by the combination of diastereofacial selection (97%) and intraanular diastereoselection (100%). (3) The olefin ene-cyclization involving trisubstituted enophile component provides an efficient approach to stereocontrol over four contiguous chiral centers. Its utility is illustrated through the short synthesis of iridoids. Thus, the stereocontrol over up to four contiguous chiral centers can be attained by the convergent combination of diastereofacial selection and intra- and extraanular diastereoselections.