Asymmetric syn-dihydroxylation of γ-substituted (2R)-N-(β,γ-enoyl)bornane-10,2-sultams
摘要:
Various gamma-substituted (2R)-N-( beta,gamma-enoyl)bornane-10,2-sultams have been examined in diastereoselective OsO4 syn-dihydroxylation. In contrast to the C(alpha)-atom, the bornane-10,2-sultam auxiliary exerts a very poor influence on the C(beta)-carbon. Spontaneous stereoselective hydrolysis of the minor diastereoisomer (3S,4S)-5c opens the way to enantiomerically pure building blocks, (C) 2000 Elsevier Science Ltd. All rights reserved.
Chiral 6-phenyl-2,3-bismethylenemethoxycarbonyl-[1,4]-dioxane as a designer synthon for an efficient and short synthesis of optically pure 2,6-dioxabicyclo[3.3.0]octane-3,7-dione
作者:Ganesh Pandey、Amrut L. Gaikwad、Smita R. Gadre
DOI:10.1016/j.tetlet.2005.11.116
日期:2006.1
Chiral 6-phenyl-2,3-bismethylenemethoxycarbonyl-[1,4]-dioxane, synthesized by the PET cyclization of 8, has been used as a designer synthon for an efficient and shortsynthesis of optically pure 2,6-dioxabicyclo[3.3.0]octane-3,7-dione.
Magnesium-mediated intramolecular reductive coupling: a stereoselective synthesis of C2-symmetric 3,4-bis-silyl-substituted adipic acid derivatives
作者:Pintu K. Kundu、Sunil K. Ghosh
DOI:10.1039/b910784c
日期:——
Chiral C2-symmetric 3,4-bis-silyl-substituted adipic acid derivatives have been synthesised by a Mg/trimethylsilyl chloride-mediated intramolecularreductivecoupling of symmetrical disiloxanes of β-silylacrylic acid N-oxazolidinone derivatives. Efficient and short syntheses of enantiomerically pure enantiomers of 2,6-dioxabicyclo[3.3.0]octane-3,7-dione have been achieved from the bis-silylated adipic
presented. (R,R)-1,5-Dioxa-2,6-dioxobicyclo[3.3.0]octane, the product of hydrogenation and subsequent cyclization, was obtained in high enantiomeric excess. This compound was transformed into synthetically useful (R)-4-hydroxyethyl-2-buten-4-olide.
Pr�paration et d�termination de la configuration des acides dihydroxy-3,4-adipiques et des ?-carboxym�thyl ??-but�nolides optiquement actifs
作者:Th. Posternak、J.-Ph. Susz
DOI:10.1002/hlca.19560390716
日期:——
AbstractLes auteurs décrivent la préparation de l'scide DL‐dihydroxy‐3,4‐adipique qu'ils ont scindé en antipodes optiques. La configuration de ces derniers a été déterminée ainsi que celle des γ‐carboxyméthyl‐δα‐ buténolides optiquement actifs. La configuration trans de l'acide δβ‐ dihydro‐muconique de F. 195 – 197° a été définitivement établie.
HIZUKA, MICHIYO;HAYASHI, NORIYUKI;KAMASHITA, TOMOKO;SUEMUNE, HIROSHI;SAKA+, CHEM. AND PHARM. BULL., 36,(1988) N 4, 1550-1553