406682-04-0Relevant articles and documents
Catalytic One-Pot Osmylation of Cyclohexadienes: Stereochemical and Conformational Studies of the Resulting Polyols
Tschamber, Theophile,Backenstrass, Frederique,Fritz, Hans,Streith, Jacques
, p. 1052 - 1060 (1992)
Catalytic double osmylation is described for a series of cyclohexadienes in acetone/H2O in the presence of the co-oxidant N-methylmorpholine N-oxide (NMO).The formation of polyols occurred stereospecifically with cyclohexadienes 3, 7, and 11a, leading thereby to tetrols 5a, and 9a and to allo-inositol (14a), respectively.To the contrary, trans-cyclohexadiene-diol 15a gave a mixture of the stereoisomeric inositols 18a (epi), 19a (neo), and 20a (chiro).High-field NMR let to clearcut conformational analyses of the polyhydroxylated derivatives.
Carbon Dioxide as a Protecting Group: Highly Efficient and Selective Catalytic Access to Cyclic cis-Diol Scaffolds
Laserna, Victor,Fiorani, Giulia,Whiteoak, Christopher J.,Martin, Eddy,Escudero-Adán, Eduardo,Kleij, Arjan W.
supporting information, p. 10416 - 10419 (2016/02/18)
The efficient and highly selective formation of a wide range of (hetero)cyclic cis-diol scaffolds using aminotriphenolate-based metal catalysts is reported. The key intermediates are cyclic carbonates, which are obtained in high yield and with high levels of diastereo- and chemoselectivity from the parent oxirane precursors and carbon dioxide. Deprotection of the carbonate structures affords synthetically useful cis-diol scaffolds with different ring sizes that incorporate various functional groups. This atom-efficient method allows the simple construction of diol synthons using inexpensive and accessible precursors and green metal catalysts and showcases the use of CO2 as a temporary protecting group. Protective Carbon: Aminotriphenolate complexes of FeIII and AlIII are highly efficient and selective catalysts for the conversion of functional (multi)cyclic oxiranes into the corresponding cis carbonates. Basic hydrolysis of the latter provides a series of useful cyclic cis-diol scaffolds in high yield. In this process, CO2 acts as both a temporary protecting group and an oxygen donor.
Chiral lithium amide base-mediated rearrangement of bis-protected meso-4,5-dihydroxy cyclohexene oxides: Enantioselective synthesis of (4R,5S) and (4S,5R)-4,5-bis(tert-butyldimethylsilyloxy)cyclohex-2-enone
O'Brien, Peter,Poumellec, Pierre
, p. 2435 - 2441 (2007/10/03)
The asymmetric synthesis of (4R,5S)- and (4S,5R)-4,5-bis(tert-butyldimethylsilyloxy)cyclohex-2-enone are described. Such bis-protected enones are useful intermediates in synthesis, and compounds with (4S,5R)-stereochemistry have previously been prepared from D-(-)-quinic acid. This paper reports the first synthesis of enones with (4R,5S)-stereochemistry. The route to the bis-protected enones involves chiral base-mediated rearrangement of meso-cyclohexene oxides to allylic alcohols followed by PDC oxidation. Two new chiral base reactions are described: rearrangement of a trans-epoxide generates an allylic alcohol of 76% ee (93% yield) whilst that of a cis-epoxide produces an allylic alcohol of 92% ee (38% yield); suggestions for the observed differences in yield and enantioselectivities are proposed.
Aminocyclohexylesters and uses thereof
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, (2008/06/13)
Aminocyclohexylester compounds, including thioesters, are disclosed. The compounds of the present invention may be incorporated in compositions and kits. The present invention also discloses a variety of in vitro and in vivo uses for the compounds and com
Chiral base-mediated rearrangement of meso-cyclohexene oxides to allylic alcohols
O'Brien, Peter,Poumellec, Pierre
, p. 8057 - 8058 (2007/10/03)
Highly enantiomerically enriched allylic alcohols have been generated by rearranging single diastereomers of meso-cyclohexene oxides using a homochiral lithium amide base. PDC oxidation of each allylic alcohol product affords a different enantiomer of a synthetically useful cyclohexenone.
SYNTHESE VON BIS(NORCARA-2,4,2',4'-TETRAENYLIDEN) UEBER EINE CARBENDIMERISIERUNG
Pilidis, Georgios
, p. 2151 - 2157 (2007/10/02)
Aus 7,7-Dibrom-3,4-isopropylidenbicycloheptan-3,4-diol (VI) und Methyllithium in Ether, sowohl bei -50 deg C als auch unter Rueckflussbedingungen entsteht das Carben, das sofort dimerisiert.Aus diesem Dimeren laesst sich in wenigen Reaktionsschritt