Study of the stereoselectivity of the nucleophilic epoxidation of 3-hydroxy-2-methylene esters
摘要:
The diastereoselectivity of the nucleophilic epoxidation of 3-hydroxy-2-methylene esters has been studied. The 3-hydroxy-2-methylene esters were obtained through a Morita-Baylis-Hillman reaction. The resulting epoxyesters were treated with thiophenol for transformation into 2,3-dihydroxy-2-((phenylthio)methyl), which upon treatment with triphosgene afforded the corresponding cyclic carbonates. (C) 2013 Elsevier Ltd. All rights reserved.
Study of the stereoselectivity of the nucleophilic epoxidation of 3-hydroxy-2-methylene esters
摘要:
The diastereoselectivity of the nucleophilic epoxidation of 3-hydroxy-2-methylene esters has been studied. The 3-hydroxy-2-methylene esters were obtained through a Morita-Baylis-Hillman reaction. The resulting epoxyesters were treated with thiophenol for transformation into 2,3-dihydroxy-2-((phenylthio)methyl), which upon treatment with triphosgene afforded the corresponding cyclic carbonates. (C) 2013 Elsevier Ltd. All rights reserved.
Key features of the β-isocupreidine (β-ICD)-catalyzed asymmetric Baylis–Hillmanreaction of aldehydes with 1,1,1,3,3,3-hexafluoroisopropyl acrylate (HFIPA) are presented. In addition, an improved method using azeotropically dried β-ICD is described.
Complementary chemistry! α‐Isocupreine (α‐ICPN) was synthesized for the first time in one step fromquinine by treatment with CF3SO3H (see scheme). This compound serves as an enantiocomplementarycatalyst to β‐isocupreidine (β‐ICD) in the Morita–Baylis–Hillman reaction.
互补化学!通过CF 3 SO 3 H处理,从奎宁一步一步合成了α-异cupreine(α-ICPN)(参见方案)。在Morita-Baylis-Hillman反应中,该化合物可作为β-异cupreidine(β-ICD)的对映体互补催化剂。
Enantioselective Synthesis of the Optically Active α-Methylene-β-hydroxy Esters, Equivalent Compounds to Morita−Baylis−Hillman Adducts, Using Successive Asymmetric Aldol Reaction and Oxidative Deselenization
作者:Isamu Shiina、Yu-suke Yamai、Takahisa Shimazaki
DOI:10.1021/jo051276y
日期:2005.9.1
The asymmetricaldol reaction of a tetra-substituted ketene silyl acetal including an alkylseleno group with aldehydes has been developed by the promotion of Sn(OTf)2 coordinated with a chiral diamine to afford the corresponding aldols having chiral quaternary centers at the α-positions. The facile oxidative deselenization of these aldol compounds produces optically active α-methylene-β-hydroxy esters