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  • allylboranes  (2)
  • (±)-3-(4-methoxycarbonyl)phenyl-2-methylprop-1-yl acetate, enzymatic hydrolysis  (1)
  • 1,6-bis(dipropylboryl)-2,4-hexadiene  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Reactions of (2,3-dimethylenetetramethylene)bis(dipropylborane) with carbonyl compounds (1993)
    Springer
    Russian chemical bulletin 42 (1993), S. 139-143 
    Details
    ISSN: 1573-9171
    Keywords: allylboranes ; conjugated dienes ; 1,2-dicarbonyl compounds ; Diels-Alder reaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract (2,3-Dimethylenetetramethylene)bis(dipropylborane) (1) prepared by borylation of 2,3-dimethylbutadienediyl dipotassium reacts with ketones to form symmetrical diols in a yield of 46–73%. [4+2]-Cycloaddition reactions of diborane1 with 1,2-dicarbonyl compounds proceed highly stereospecifically, affording onlycis-isomers of 4,5-dimethylenecyclohexane1, 2-diols.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00699996
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Unprecedented stereoselectivity in a reaction of a novel diboron compound — 1,6-bis(dialkylboryl)-2,4-hexadiene with carbonyl compounds (1993)
    Springer
    Russian chemical bulletin 42 (1993), S. 144-148 
    Details
    ISSN: 1573-9171
    Keywords: 1,6-bis(dipropylboryl)-2,4-hexadiene ; allylboration ; iodocyclization ; 3,7-dioxabicyclo[3.3.0]octane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Arylboration of carbonyl compounds with a novel diboron reagent — 1,6-bis(dipropylboryl)-2,4-hexadiene — proceeds in a regio- and stereospecific way to give exclusivelyd,l-diastereomers of the corresponding 2,3-divinylsubstituted 1,4-diols. Their iodocyclization allowed preparation of 3,7-dioxabicyclo[3.3.0]octane derivatives withcis-junction of the tetrahydrofuran rings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00699997
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Reductivetrans-2,6-diallylation of pyridines with allylboranes. Synthesis oftrans- andcis-2,6-diallyl-1,2,5,6-tetrahydropyridines and their deuterated derivatives (1994)
    Springer
    Russian chemical bulletin 43 (1994), S. 645-656 
    Details
    ISSN: 1573-9171
    Keywords: allylboranes ; triallylborane complexes ; allylboration ; pyridines ; reductivetrans-2,6-diallylation of pyridines ; cis- andtrans-diallyl-1,2,5,6,-tetrahydropyridines ; cis- andtrans-2,6-dipropylpiperidines ; trans-cis-isomerization.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The reductivetrans-2,6-diallylation of pyridines with triallyl- and allyl(dialkyl)boranes has been discovered. Heating (40–100 °C) of pyridine, deuteropyridine, or 3-bromopyridine complexes with triallylborane in the presence of alcohols (ROH or CH3OD), water, or Et2NH results in the respectivetrans-2,6-diaIlyl-1,2,5,6-tetrahydropyridines (2,3,22, or25) in 20–97 % yields. A preparative method for the isomerization oftrans-2,6-diallyl compounds2 and25 into the respectivecis-isomers4 and28 by heating them with triallyl- or allyl(dialkyl)boranes (125–150 °C) has been suggested. The hydrogenation oftrans- orcis-2,6-diallyl-1,2,5,6-tetrahydropyridines gavetrans- orcis-2,6-dipropylpiperidines, respectively. Thecis- andtrans-configurations of compounds2 and4 were established by analyzing the NMR spectra ofN-benzyl (7 and13) andN,N-dimethyl (6 and 14) derivatives of piperidine derivatives5 and8. A possible mechanism for the reductive diallylation of pyridines has been discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00699842
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    A chemo-enzymatic approach to optically active 3-(4-methoxycarbonyl)phenyl-2-methyl-1-propanols (1995)
    Springer
    Russian chemical bulletin 44 (1995), S. 743-748 
    Details
    ISSN: 1573-9171
    Keywords: pancreatic lipase ; (±)-3-(4-methoxycarbonyl)phenyl-2-methylprop-1-yl acetate, enzymatic hydrolysis ; 3-(4-methoxycarbonyl)phenyl-2-methyl-2-propen-1-ol, yeast reduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract With a view to obtaining both enantiomers of 3-(4-methoxycarbonyl)phenyl-2-methyl-1-propanols, (R)-1 and (S)-1, from the respective racemate, (±)-1, the hydrolysis of its acetate, (±)-2, in the presence of porcine pancreatic lipase (PPL) has been studied. The optical puriry of (R)-1 and (S)-1 thus obtained was unsatisfactory (ee 22–27%), and could not be increased beyondee 33% by repeated enzymatic hydrolysis of the unconverted fraction of the acetate. In contrast with this, the biohydrogenation of 3-(4-methoxycarbonyl)phenyl-2-methyl-2-propen-1-ol (4) with fermentingSaccharomyces cerevisiae afforded (S)-1 of considerably higher optical purity (ee 41–90 %, depending on the strain). The stereochemical correlation of the products obtained in the two biochemical processes under study shows that the PPL-catalyzed hydrolysis of (±)-2 produces preferably (R)-1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00698514
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    Paper (German National Licenses)
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