Studies on a New Access to <i>Z</i>-Ethylenic Pseudodipeptides Based on Ring-Closing
Metathesis: Obtention and Reductive Cleavage of <i>N</i>-Arylsulfonyl
Dihydropyridones
作者:Lucie Vandromme、Olivier N’Guyen Van Buu、François Guibé、Sophie Bezzenine-Lafollée
DOI:10.1055/s-0029-1217328
日期:——
In the reaction with tert-butyloxycarbonyl anhydride (Boc2O), N-(o-vinylacetyloxy)benzenesulfonyl allylic amines 4a-c undergo concomitant O to N acyl migration to give N-(o-vinylacetyloxy)-N-(o-tert-butoxycarbonyloxy)benzenesulfonyl allylic amines 16a-c. In the presence of Grubbs’ second-generation catalyst, 16a-c are converted into N-arylsulfonyl-3,6-dihydropyridones 17a-c. The Boc group was removed from 17b and the resulting 18 was reductively cleaved with LiAlH4 to the ring-opened N-arylsulfonylamino alcohol 20 and with DIBAL to the ring-opened N-arylsulfonylamino aldehyde 21 that are close N-protected precursors of the Z-ethylenic pseudopeptidic analogue of l-Phe-Gly.
在与叔丁氧基羰基酸酐 (Boc2O) 的反应中,N-(邻乙烯基乙酰氧基)苯磺酰基烯丙胺 4a-c 伴随 O 至 N 酰基迁移,得到 N-(邻乙烯基乙酰氧基)-N-(邻叔丁氧基羰氧基) )苯磺酰烯丙胺16a-c。在格鲁布斯第二代催化剂存在下,16a-c 转化为 N-芳基磺酰基-3,6-二氢吡啶酮 17a-c。从17b中除去Boc基团,并将所得的18用LiAlH 4 还原裂解成开环的N-芳基磺酰氨基醇20,并用DIBAL还原裂解成开环的N-芳基磺酰氨基醛21,它们是Z-的紧密N-保护的前体L-Phe-Gly 的乙烯假肽类似物。