Simple Preparation of Diamondoid 1,3-Dienes via Oxetane Ring Opening
摘要:
The transformations of apical mono- and bisacetyl diamondoids to the respective oxetanes and subsequent acid-catalyzed ring opening/dehydration lead to diamondoidyl mono- and bis-1,3-dienes in high preparative yields.
mixtures of isomers and substantial polymerization. The reaction took place under exceptionally mild reaction conditions and very low catalyst loading (0.5 mol %). DFT calculations disclose the mechanistic features of the isomerization and account for the high selectivity displayed by the B(C6 F5 )3 catalyst. The synthetic applicability of the newreaction is demonstrated by the preparation of γ-chiral
Stereospecific Consecutive Epoxide Ring Expansion with Dimethylsulfoxonium Methylide
作者:Ekaterina D. Butova、Anastasiya V. Barabash、Anna A. Petrova、Christian M. Kleiner、Peter R. Schreiner、Andrey A. Fokin
DOI:10.1021/jo101330p
日期:2010.9.17
Consecutive ring-expansion reactions of oxiranes with dimethylsulfxonium methylide were studied experimentally and modeled computationally at the density functional theory (DFT) and second-order Møller−Plesset (MP2) levels of theory utilizing a polarizable continuum model (PCM) to account for solvent effects. While the epoxide to oxetane ring expansion requires 13−17 kcal mol−1 activation and occurs
homoallyl sulfones were prepared from homoallyl alcohols, which are easily accessible through the recently reported Lewis acid isomerization of oxetanes. The iridium-catalyzed asymmetric hydrogenation of homoallylic sulfones afforded γ-chiral sulfones with excellent enantioselectivities (up to 98% ee). The synthetic potential of this novel methodology was demonstrated by the total synthesis of (R)-(−)-curcumene
报道了一种制备手性甲基苄基化合物的新方法。末端高烯丙基砜是由高烯丙醇制备的,可以通过最近报道的氧杂环丁烷的路易斯酸异构化轻松获得。铱催化的高烯丙基砜的不对称氢化提供了具有优异对映选择性(高达 98% ee)的 γ-手性砜。 ( R )-(−)-姜黄烯的全合成证明了这种新颖方法的合成潜力。
US4034038A
申请人:——
公开号:US4034038A
公开(公告)日:1977-07-05
Simple Preparation of Diamondoid 1,3-Dienes via Oxetane Ring Opening
作者:Andrey A. Fokin、Ekaterina D. Butova、Lesya V. Chernish、Natalie A. Fokina、Jeremy E. P. Dahl、Robert M. K. Carlson、Peter R. Schreiner
DOI:10.1021/ol070920n
日期:2007.6.1
The transformations of apical mono- and bisacetyl diamondoids to the respective oxetanes and subsequent acid-catalyzed ring opening/dehydration lead to diamondoidyl mono- and bis-1,3-dienes in high preparative yields.