On the Susceptibility of Organic Peroxy Bonds to Hydride Reduction
摘要:
Reduction of organic molecules that contain a peroxy bond is broadly considered as a "risky" and uncertain operation when cleavage of the peroxy linkage is not desired. For this reason, such reduction steps are normally avoided at the planning stage of the synthesis when possible. As a natural consequence, the information in the literature about the susceptibility of organic peroxy bonds to reducing species is scant. In this work the tolerance of organic peroxy bonds to some common hydride reductants was examined systematically for the first time. Using reduction of ester group to alcohol as a probe, LiAlH4, LiAlH((OBU)-B-t)(3), LiBHEt3, and LiBH4 were found to be significantly better than other reductants examined when taking into consideration both the completeness of the reduction of ester groups and the peroxy bond survival rate. LiBH4 appeared to be the most suitable reductant for the reduction under discussion, not only because of the high reduction yields/excellent compatibility with peroxy bonds, but also because of the advantages in practical aspects. The results disclosed herein may (hopefully) provide a handy reference for dealing with reduction of other peroxy bond-containing molecules in the future.
设计和合成了几种螺过氧抗疟疾化合物,使用过氧化氢在UHP中(脲-H 2 O 2络合物)作为过氧键的来源。掺入H 2 O 2在当前情况下,由于在酮羰基上存在羟基γ或δ,形成五元或六元环状半缩酮的可能性极大地促进了通过缩酮交换反应进入有机分子骨架。当迈克尔受体中的吸电子基团是硝基时,在水氧化条件下,过氧环的闭合很容易发生。与过氧环稠合的苯环的存在有效地降低了闭环步骤过渡态的自由度,并使原本非常困难的七元1,2-二氧戊环很容易通过分子内迈克尔加成而形成。
Synthesis of benzene-fused 1,7,8-trioxa-spiro[5.6]dodecanes
作者:Hong-Xia Jin、Yikang Wu
DOI:10.1016/j.tetlet.2005.08.031
日期:2005.10
Two novel organic peroxides with one or two benzene rings fused to a 1,7,8-trioxaspiro[5.6]dodecan framework were synthesized, which provided the first examples of employing Kobayashi ' s methodology in the synthesis of seven-membered peroxy rings. CSA was found to be a potent catalyst for introduction of the hydroperoxyl group, making a useful complement to Kobayashi ' s methodology in constructing spiroperoxides. (c) 2005 Elsevier Ltd. All rights reserved.