105183-24-2Relevant academic research and scientific papers
Stereoselective Syntheses of Branched-Chain Carbohydrates Bearing Furan and Pyrrole Moieties
Kraehenbuehl, Karin,Vogel, Pierre
, p. 8595 - 8598 (1995)
The racemic 7-oxanorborn-5-en-2-one has been converted into 1,5-anhydro-3-deoxy-3--α-galacto furanose and into 1,5-anhydro-3-deoxy-3--α-galactofuranose derivatives.
The Demjanov and Tiffeneau-Demjanov one-carbon ring enlargements of 2-aminomethyl-7-oxabicyclo[2.2.1]heptane derivatives. The stereo- and regioselective additions of 8-oxabicyclo [3.2.1]oct-6-en-2-one to soft electrophiles
Fattori, Daniela,Henry, Sylvie,Vogel, Pierre
, p. 1649 - 1664 (2007/10/02)
Nitrosation of 7-oxabicyclo[2.2.1]hept-5-en-2-exo-ylmethyl amine (20) gave 7-oxabicydo[2.2.1]hept-5-en-2-exo-methanol (22) whereas 7-oxabicyclo[2.2.1]hept-5-en-2-endo-ylmethylamine (21) afforded a 1:1 mixture of 7-oxabicydo[3.2.1]oct-6-en-2-ols (23) and 8-oxabicydo[3.2.1]oct-3-en-2-ols (24). Nitrosations of 2-exo- (28) and 2-endo-aminomethyl-7-oxabicyclo[2.2.1]hept-5-en-2-ol (29) gave mixtures of 8-oxabicydo[3.2.1]oct-6-en-2-one (25) and 8-oxabicydo[3.2.1]oct-6-en-3-one (37). The preference for the C(3) methylene group migration giving 25 was the best (12:1) in the case of the 2-endo-aminomethyl alcohol 29. Compared with the nitrosations of bicydo[2.2.1]heptane analogues, the 7-oxa bridge in 28 and 29 enhances the preference for the C(3) methylene group migration vs. the C(1) methine group migration. The Tiffeneau-Demjanov one-carbon ring enlargement reactions of 2-exo-aminomethyl-7-oxabicyclo[2.2.1]hepta-2-endo-ol (30). 2-exo-aminomethyl-5-chloro (32) and 2-exo-aminomethyl-6-chloro-7-oxabicyclo[2.2.1]hept-5-en-endo-ol (33) are also reported. Under kinetically controlled conditions, 8-oxabicydo[3.2.1]oct-6-en-2-one (25) adds to electrophiles EX=PhSeCl, PhSeBr. 2,4-(NO)2C6H3SCl with high stereo- and regioselectivity giving the corresponding 8-oxabicyclo [3.2.1]-octan-2-ones where E substitutes the exo position of C(6) and X the exo position of C(7).
''Naked Sugars''as Synthetic Intermediates. Total Synthesis of L-Daunosamine
Warm, Aleksander,Vogel, Pierre
, p. 5348 - 5353 (2007/10/02)
The ''naked sugars'' are optically pure synthetic intermediates.Their advantage compared with natural sugars is that they possess a number of unsubstituted carbon atoms that can be substituted stereospecifically through direct procedures. (1S,2R,4S)-2--7-oxabicyclohept-5-ene-2-carbonitrile ((+)-1) is an example of a ''nuked sugar''.Electrophilic reagents add to the C(5), C(6) double bond, giving the corresponding adducts where the electrophile substitutes the exo position of C(6) and the nucleophile the endo position at C(5).This principle was used to prepare (1R,4R,5R)-5-endo-chloro-7-oxa-2-bicycloheptanone (13), which was monomethylated stereoselectively in the exo position at C(3), giving (+)-(1R,3S,4R,5R)-5-endo-chloro-3-exo-methyl-7-oxa-2-bicycloheptanone (14).The latter was transformed stereospecifically indo L-daunosamine (3-amino-2,3,6-trideoxy-L-lyxo-hexose).The (-)-camphanic acid used to engender asymmetry was recovered at an early stage of the synthesis.
Regioselectivity of Electrophilic Additions to 7-Oxabicycloheptenes Controlled by Remote Substituents. Arenesulfonyl Substituted 7-Oxabicycloheptenes as Stereo- and Regioselective Chiral Dienophiles
Black, Kersey A.,Vogel, Pierre
, p. 5341 - 5348 (2007/10/02)
Benzeneselenyl, 2-nitrobenzenesulfenyl, and 2,4-dinitrobenzenesulfenyl chlorides added to 2-endo-acetoxy-7-oxabicyclohept-5-ene-2-exo-carbonitrile (11) in an anti fashion with complete stereo- and regioselectivity, giving the adducts 13a-c in which
