An Easy Access to Bicyclic Peptides with an Octahydro[2H]pyrazino[1,2-a]pyrazine Skeleton
作者:Vladimir N. Belov、Christian Funke、Thomas Labahn、Mazen Es-Sayed、Armin de Meijere
DOI:10.1002/(sici)1099-0690(199906)1999:6<1345::aid-ejoc1345>3.0.co;2-2
日期:1999.6
α-amino esters 9a,b yielded (4′S,9a′R)-14a (≡15a) and (4′S,9a′R)-14b (≡15b), (4′S,7′S,9a′R)-14c and (4′R*,7′S*,9a′S*)-15c. The formation of compounds with three stereogenic centers 14c and 15c was accompanied by partial racemization. The versatility of the reported reaction sequence is limited by the steric availability of the secondary amino group in the intermediates 4, 9 and 10, as well as in the
新路由到八氢(环丙烷-1,1' - [2 ħ ] -吡嗪并[1,2一]吡嗪)-3',6',9'-三酮12 - 15已经研制成功。伯胺的Michael加成到甲基2-ME或叔丁基2-吨卜2-氯-2- cyclopropylideneacetates,随后DCC-或EDC诱导用的Boc-或FmocGlyOH,脱保护和环化偶联导致α-氨基酯4a – c和氯六氢二氮杂二酮5a – c,或在2- t Bu与α-氨基酯7的情况下只。这与(反应顺序小号)-BocPheOH和(小号)-BocTrpOH非对映选择性得到(3' - [R,5'小号) - 9A,B和(2'小号,6' - [R )- 11A,B为主要产品。进一步的肽偶联,脱保护和与4a - c的环化反应生成八氢螺(环丙烷-1,1'-[2 H ]吡嗪并[1,2- a ]吡嗪)-3',6',9'-三酮(7 'S,9a 'S)-12a – d,(6a 'S,11a