124355-70-0Relevant academic research and scientific papers
Tandem application of C-C bond-forming reactions with reductive ozonolysis
Willand-Charnley, Rachel,Dussault, Patrick H.
, p. 42 - 47 (2013)
Several variants of reductive ozonolysis, defined here as the in situ generation of aldehydes or ketones during ozonolytic cleavage of alkenes, are demonstrated to work effectively in tandem with a number of C-C bond-forming reactions. For reactions involving basic nucleophiles (1,2- addition of Grignard reagents, Wittig or Horner-Emmons olefinations, and directed aldol reactions of lithium enolates), the one-pot process offers a rapid and high-yielding alternative to traditional two-step protocols.
New Chiral Auxiliaries Derived from β-Pinene: Their Use in the Asymmetric Reduction of β-Keto-Esters
Vasconcellos, Mario Luiz,d'Angelo, Jean,Desmaele, Didier,Costa, Paulo R. R.,Potin, Dominique
, p. 353 - 356 (2007/10/02)
3-Ketobutyrates 6, derived from chiral auxiliary alcohols 5 - themselves efficiently prepared from β-pinene 4 - were reduced with zinc borohydride, giving 3-hydroxybutyrates 7 with 2-70percent de, depending on the nature of aryl group in alcohols 5.
Hydroboration. 85. Synthesis and Hydroboration of (-)-2-Phenylapopinene. Comparison of Mono(2-phenylapoisopinocampheyl)borane with Its 2-Methyl and 2-Ethyl Analogues for the Chiral Hydroboration of Representative Alkenes
Brown, Herbert C.,Weissman, Steven A.,Perumal, P. T.,Dhokte, U. P.
, p. 1217 - 1223 (2007/10/02)
The dehydration of (+)-2-phenylnopinol with POCl3 provides a new chiral ligand, (-)-2-phenylapopinene (87percent ee), with higher steric requirements than those of α-pinene or its 2-ethyl analogue.Hydroboration of (-)-2-phenylapopinene with BH3*SMe2 (BMS) (1.2:1 ratio, respectively) provides an equilibrium mixture of the mono(2-phenylapoisopinocampheyl)borane (PapBH2) and the corresponding dialkylborane.Treatment of this mixture with tetramethylethylenediamine (TMEDA) precipitates crystalline (PapBH2)*TMEDA.Liberation of the PapBH2 using BF3*OEt2 provides the monoalkylborane in >99percent ee, thus providing the required reagent in significantly higher optical purity than the starting olefin.Hydroboration of a series of representative olefins using PapBH2 at -25 deg C, followed by oxidative workup, provides the corresponding chiral alcohols in unexpectedly lower enantiomeric purities than those obtained from the 2-methyl and 2-ethyl analogues under identical conditions.Liberation of the starting auxiliary from the borane reagent provides (-)-2-phenylapopinene of >99percent ee.The hydroboration of (-)-2-phenylapopinene with 9-borabicyclononane (9-BBN) at 28 deg C in THF proceeds at an extremely retarded rate compared to its 2-methyl and 2-ethyl analogues.Fortunately, this lack of reactivity is easily circumvented by reacting PapBH2 with 1,5-cyclooctadiene at room temperature for 1 h, followed by thermal isomerization to provide the desired trialkylborane.
