1196-00-5Relevant academic research and scientific papers
Incorporation of an allene unit into α-pinene via β- elimination
Kilbas, Benan,Azizoglu, Akin,Balci, Metin
, p. 1449 - 1456 (2006)
The two double-bond isomers 3-iodo-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene (6b) and 3-iodo-4,6,6-trimethylbicyclo[3.1.1]hept-2-ene (11) were synthesized by reacting 2,6,6-trimethylbicyclo[3.1.1]heptan-3-one (9) with hydrazine, followed by treatment with I2 in the presence of Et3N. Treatment of 11 with t-BuOK as base in diglyme at 220 resulted in the formation of 9 and 6,6-dimethyl-4-methylidenebicyclo[3.1.1]hept-2-ene (12). For the formation of 9, the cyclic allene 7 is proposed as an intermediate. Treatment of the second isomer, 6b, with t-BuOK at 170 gave rise to the diene 12 and the dimerization product 17. The underlying mechanism of this transformation is discussed. On the basis of density-functional-theory (DFT) calculations on the allene 7 and the alkyne 15, the formation of the latter as the intermediate was excluded. Verlag Helvetica Chimica Acta AG.
Oxidoreduction between Cycloalkanols and the Corresponding Cycloalkanones in the Cultured Cells of Nicotiana tabacum. Simulation of the Time Courses in the Oxidoreduction
Izumi, Shunsuke,Suga, Takayuki
, p. 1715 - 1720 (1988)
A method for the simulation of the time courses in the oxidation of cycloalkanols and the reduction of cycloalkanones in the cultured cells of Nicotiana tabacum was developed on the basis of the permeability of these compounds into the cultured cells and the 13C NMR chemical shift of the carbonyl carbon of the cycloalkanones.Further, the method has been applied to the simulation of the time courses in the oxidation of (+)-borneol and (+)-isopinocampheol and the reduction of (-)-carvomenthone in the cultured cells of N. tabacum.
An improved procedure for the separation of (+) or (-)-isopinocampheol, the major side product of the oxidation workup procedure of Brown's asymmetric crotylborations
Hua, Zhengmao,Jin, Zhendong
, p. 7695 - 7697 (2007)
Separation of (+) or (-)-isopinocampheol, the major side product of the oxidation workup procedure of Brown's asymmetric reactions such as crotylborations from the desired product is quite tedious and often requires repeated column chromatography. It is discovered that a sublimation process can be used to easily separate this major side product.
Synthesis and ultraviolet absorption characteristics of 4-arylidene isopinocamphones from α-pinene
Wang, Jia-Y.U.,Wang, Peng-N.A.,Yang, Jin-Lai,Shen, Jia,Xu,Wang, Shi-F. A.
, p. 7779 - 7784 (2014)
A new series of 4-arylidene isopinocamphones were synthesized from α-pinene which is a natural chemical from pine tree and their ultraviolet absorption characteristics were investigated. (+)Isopinocamphone was obtained from α-pinene by hydroboration-oxidation and then it was reacted with benzaldehyde, p-methylbenzaldehyde, p -methoxybenzaldehyde, p-chlorobenzaldehyde, furfural and p -nitrobenzaldehyde in the presence of alkali catalysts to get 4-arylidene isopinocamphones including 2-benzylidene-4,6,6-trimethylbicyclo[3.1.1]heptan-3-one (1), 2,6,6-trimethyl-4-(4-methyl benzyl)bicyclo[3.1.1]heptane-3-one (2), 2-(4-methoxybenzylidene)-4,6,6-trimethylbicyclo[3.1.1] heptan-3-one ( 3 ), 2-(4-chlorobenzylidene)-4,6,6-trimethylbicyclo[3.1.1]heptan-3-one (4 ), 2-(furan-2-methylene)-4,6,6-trimethylbicyclic [3.1.1] heptane-3-one (5) and 2,6,6-trimethyl-4-(4-nitrobenzylidene)bicyclo[3.1.1]heptan-3-one (6). he structures of 4-arylidene isopinocamphones were determined by FT-IR, 1H NMR, 13/C NMR and GC-MS technique. Their ultraviolet absorption characteristics and light stability was further examined. The results showed that compounds 1 , 2, 3 and 5 could be used as Btype UV absorbents, compounds 4 and 6 could be used as A-type UV absorbents and compounds 6 had both functions as UV-A and UVB types absorbents. The light stability sequence of these compounds was (2 ) > (1) ≈ (3) ≈ (4) ≈(6) > (5).
Biology-oriented synthesis of a withanolide-inspired compound collection reveals novel modulators of hedgehog signaling
venda, Jakub,Sheremet, Michael,Kremer, Lea,Maier, Luk,Ziegler, Slava,Kumar, Kamal,Waldmann, Herbert,Bauer, Jonathan O.,Strohmann, Carsten
, p. 5596 - 5602 (2015)
Biology-oriented synthesis employs the structural information encoded in complex natural products to guide the synthesis of compound collections enriched in bioactivity. The trans-hydrindane dehydro-δ-lactone motif defines the characteristic scaffold of the steroid-like withanolides, a plant-derived natural product class with a diverse pattern of bioactivity. A withanolide-inspired compound collection was synthesized by making use of three key intermediates that contain this characteristic framework derivatized with different reactive functional groups. Biological evaluation of the compound collection in cell-based assays that monitored biological signal-transduction processes revealed a novel class of Hedgehog signaling inhibitors that target the protein Smoothened. BIOS delivers a collection of compounds with the trans-hydrindane dehydro-δ-lactone scaffold, which are based on the withanolide natural products, in a stereoselective fashion. A biological investigation of the compounds revealed novel and potent inhibitors of the Hedgehog signaling pathway, which bind to the protein Smoothened.
Part II: Transformations of α and β-Pinene Oxides over Binary Oxide Catalysts of Alumina-Rare Earth Oxides
Jayasree, Janakiamma,Narayanan, Cadavallore S.
, p. 89 - 94 (1995)
The catalytic activity of binary oxides of Al2O3-Eu2O3, Al2O3-Sm2O3, Al2O3-NdO3, Al2O3-Pr6O11, and Al2O3-Y2O3 were checked in the transformations of α and β-pinene oxides.Al2O3-Eu2O3 and Al2O3-Nd2O3 are found to be best catalysts for α-pinene oxide isomeriztion.Among the oxiranes, α-pinene oxide showed more activity mainly yielding 2,2,3-trimethyl cyclopentene-1-acetaldehyde. β-pinene oxide produced trans-myrtanal and myrtanol.
Hydroboration. 91. Improved Procedure for the Synthesis of Optically Pure Bis-adducts, N,N,N',N''-Tetramethylethylenediamine-2-organylapoisopinocampheylboranes, from the Corresponding 2-Organylapopinenes of Lower Optical Purity. Conversion of These Adducts into 2-Organylapoisopinocamp...
Brown, Herbert C.,Dhokte, Ulhas P.
, p. 2365 - 2369 (1994)
The higher analogues of α-pinene, such as 2-ethyl-, 2-n-propyl-, 2-isobutyl-, 2-phenyl-, and 2-isopropylapopinenes, were treated with borane-methyl sulfide (BMS) in the stoichiometry of 1.2:1, respectively, in anhydrous tetrahydrofuran (THF) at 25 deg C, obtaining an equilibrium mixture of 2-organylapoisopinocampheylboranes (2-R-apoisopinylborane, RapBH2) as major and bis(2-organylapoisopinocampheyl)borane as minor constituents.Treatment of the equilibrium mixture of boranes with tetramethylethylenediamine (TMEDA) at 34 deg C readily and selectively provided the optically pure bis(2-organylapoisopinocampheylborane)*TMEDA adducts, (RapBH2)2*TMEDA, in satisfactory yield.This reaction is quite general and appears to be broadly applicable to the conversion of the sterically bulkier 2-organylapopinenes (2-R-apopinenes) with widely varied steric requirements and lower optical purity (87-92percent ee) into the corresponding optically pure (RapBH2)2*TMEDA derivatives, approaching >/= 99percent ee.Treatment of the crystalline bis-adduct in ethyl ether with BF3*EE precipitates (BF3)2*TMEDA and provides RapBH2 of essentially >/= 99percent ee, enantiomerically purer than the 2-R-apopinenes of 87-92percent ee utilized for these preparations.
Chiral terpene auxiliaries V: Synthesis of new chiral γ-hydroxyphosphine oxides derived from α-pinene
Kmieciak, Anna,Krzemiński, Marek P.
supporting information, p. 2493 - 2499 (2019/12/11)
New chiral regioisomeric γ-hydroxyphosphine ligands were synthesized from α-pinene. The key transformation was the thermal [2,3]-sigmatropic rearrangement of allyldiphenylphosphinites, obtained from (1R,2R,4S,5R)-3-methyleneneoisoverbanol and (1R,2R,3R,5R)-4-methyleneneoisopinocampheol, to allylphosphine oxides. Hydroxy groups were introduced stereoselectively through a hydroboration–oxidation reaction proceeding from the less hindered site providing a trans relationship between the hydroxy and the phosphine substituents.
One-Pot Absolute Stereochemical Identification of Alcohols via Guanidinium Sulfate Crystallization
Brummel, Beau R.,Lee, Kinsey G.,McMillen, Colin D.,Kolis, Joseph W.,Whitehead, Daniel C.
, p. 9622 - 9627 (2019/12/02)
A novel technique for the absolute stereochemical determination of alcohols has been developed that uses crystallization of guanidinium salts of organosulfates. The simple one-pot, two-step process leverages facile formation of guandinium organosulfate single crystals for the straightforward determination of the absolute stereochemistry of enantiopure alcohols by means of X-ray crystallography. The strong hydrogen bonding network drives the stability of the crystal lattice and allows for a diverse range of organic alcohol substrates to be analyzed.
A non-dissociative open-flask hydroboration with ammonia borane: Ready synthesis of ammonia-trialkylboranes and aminodialkylboranes
Ramachandran, P. Veeraraghavan,Drolet, Michael P.,Kulkarni, Ameya S.
supporting information, p. 11897 - 11900 (2016/10/09)
Under open-flask conditions, ammonia borane hydroborates olefins in refluxing tetrahydrofuran. Unlike conventional hydroboration, the Lewis base (ammonia) is not dissociated from the boron center. Terminal alkenes selectively provide ammonia-trialkylborane complexes. On the other hand, internal alkenes afford aminodialkylboranes via a metal-free hydroboration-dehydrogenation sequence. Alkaline hydrogen peroxide oxidation of the products provides the corresponding alcohols in high yields.
