KOBAYASHI Kazuhiro Hokkaido Univ., Fac.of Eng., Instructor, 工学部, 助手 (90161976)
ORITO Kazuhiko Hokkaido Univ., Fac.of Eng., Instructor, 工学部, 助手 (20109482)
TOKUDA Masao Hokkaido Univ., Fac.of Eng., Assoc.Professor, 工学部, 助教授 (80001296)
1. New Synthesis of macrolides based on beta-scission of alkoxyl radicals. A simple new method was devised for the synthesis of macrolides based on a consecutive intramolecular homolytic addition-bata-scission of alkoxyl radicals. 11 to 16-Membered macrocyclic lactones including ((〕SY.+-.〔))-recifeiolide have been efficiently prepared by this new method.
2. New method for the transformation of steroids into physiologically-active 18- or 19- norsteroids based on bata-scission of alkoxyl radicals New method for transformation of steroids into 18- and 19-norsteroids and ring-A- aromatized steroids was devised. Several physiologically-active 18-, and 19-norsteroids were synthesized by this method.
3. Synthesis of heterocyclic quinones based on a new [2+3] photoaddition. A one-step formation of 2,3-dihydronaphto[2,3-b]furan-4,9-diones by a new [2+3] type regioselective photoaddition of 2-hydroxy-1,4-naphthoquinones with a variety of alkenes wa13EA\ : s devised. The dihydronaphthofurandiones were readily transformed into naphtho[2,3-b]furan-4,9-diones including a natural quinone, maturinone. Efficient one-step synthesis of 2,3-dihydro-1H- benz[f]indole-4,9-diones of 1H-benz[f]indole-4,9-diones ba13EA\ : sed on an unprecedented 2+3 type regioselective photoaddition of 2-aminoquinone with various alkenes was also devised.
4. New synthesis of physiologically-active heterosteroids. A new method was devised for transforming steroidal cyclic ketones into steroidal cyclic amines, cyclic sulfies, cyclic tellurides, and cyclic selenides with the same ring size via 5 to 6 st13EA\ : eps. A number of heterosteroids were synthesized by this method.
5. Other Results stereoselective synthesis of 2,5-disubstituted pyrrolidines by anodic oxidation of delta-alkenylamines, new method for remote functionalization, new synthesis of lignanes, and new method for the annelatioin etc. were devised.