BOHHClClHFelkin-Anh (Re)disfavouredsyn-pentanedipole-dipolevs.OBClHHClHfavouredOHClHHClH≡OHClHHClH≡ClOHClThe allyl borane reagent reacts through a closed (cyclic) transition state and so weneed to draw a chair-like arrangement of atoms. The first representation shows thereaction proceeding through attack predicted by the Felkin-Anh model. This does notoccur due to the syn-pentane interaction (sterics) or the destabilising alignment of theC–Cl dipoles (electronics). Instead the reaction must proceed through anti-Felkin-Anhattack on the aldehyde ...BOHHClClHFelkin-Anh (Re)disfavouredsyn-pentanedipole-dipolevs.OBClHHClHfavouredOHClHHClH≡OHClHHClH≡ClOHCl... in this arrangement we minimise the syn-pentane interaction (C–Cl eclipses C–H).Once again the hardest part is unravelling the 3D representation into a standardskeletal representation. I have tried to make it easier by highlighting in bold all theatoms in the plane of the paper. Thus you should see that two hydrogens and achloride are on the top face.Note: the reaction could proceed through the polar-Felkin-Anh transition state with thechloride perpendicular to the carbonyl but this is unlikely as the isopropyl group wouldeclipse the other chloride.
アルケンの反応1、syn付加とanti付加
警告物質が窒素利用を制御する作用点を解明光合成細菌を用いたバイオものづくり
い・ろ・は・す 天然水 PET ラベルレス(2000ml*8本入)【いろはす(I LOHAS)】[水 ミネラルウォーター]
斎藤雅一研究室
Nucleophilic allylic substitution via SN2 [closed]