[²H₂₆]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2841–2845, doi:10.3762/bjoc.9.319

• Christian A. Citron Jeroen S. Dickschat Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany 10.3762/bjoc.9.319 Abstract During growth on fully deuterated medium the volatile terpene [2H26]-1-epi-cubenol was released by the actinomycete

• Streptomyces griseus. This compound represents the first completely deuterated terpene obtained by fermentation. Despite a few previous reports in the literature the operability of this approach to fully deuterated compounds is still surprising, because the strong kinetic isotope effect of deuterium is known

• ; terpenes; Introduction The actinomycete Streptomyces griseus is a producer of three terpenes, 2-methylisoborneol (2-MIB, 1), (+)-caryolan-1-ol (2), and (+)-1-epi-cubenol (3, Figure 1). The biosynthesis of 2 and 3 requires the action of well characterized terpene cyclases [1][2], while the biosynthesis of

Caryolene-forming carbocation rearrangements

• Quynh Nhu N. Nguyen and
• Dean J. Tantillo

Beilstein J. Org. Chem. 2013, 9, 323–331, doi:10.3762/bjoc.9.37

• intermediates; terpene; Introduction The cytotoxic sesquiterpenol caryol-1(11)-en-10-ol (1, Figure 1) was isolated by Barrow et al. in 1988 during an investigation of antiviral/antitumor compounds from New Zealand marine invertebrates [2]. Similar sesquiterpenoids were also found in Campanella fungi

• formation, applying the principles derived from previous theoretical studies on terpene-forming carbocation rearrangements [8]. In this mechanism, formation of the C1–C11 bond was expected to result in secondary carbocation B, in analogy to previously characterized pathways to sesquiterpenes containing 11

Stereoselective synthesis of trans-fused iridoid lactones and their identification in the parasitoid wasp Alloxysta victrix, Part II: Iridomyrmecins

• Robert Hilgraf,
• Nicole Zimmermann,
• Lutz Lehmann,
• Armin Tröger and
• Wittko Francke

Beilstein J. Org. Chem. 2012, 8, 1256–1264, doi:10.3762/bjoc.8.141

• monoterpenes de novo [33] but they are also able to sequester glycosidically bound terpene precursors from their food plants [51][52][53] which is highly interesting with regards to the evolution of insect-plant relationships and insect defense chemistry. At present, nothing is known about the formation of

Carbohydrate-auxiliary assisted preparation of enantiopure 1,2-oxazine derivatives and aminopolyols

• Marcin Jasiński,
• Dieter Lentz and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2012, 8, 662–674, doi:10.3762/bjoc.8.74

• known protocols employing terpene units [62] and carbohydrate-derived auxiliaries [63][64] for the asymmetric synthesis of the 1,2-oxazine derivatives. More recently, the use of (–)-menthol as a chiral auxiliary was presented for the separation of diastereomeric 6H-1,2-oxazines [65][66]. Subsequent

Tertiary alcohol preferred: Hydroxylation of trans-3-methyl-L-proline with proline hydroxylases

• Christian Klein and
• Wolfgang Hüttel

Beilstein J. Org. Chem. 2011, 7, 1643–1647, doi:10.3762/bjoc.7.193

• ]. Other less common approaches include stereospecific enzyme-catalyzed hydrolyses of epoxides, stereoselective additions to ketones with hydroxynitrile lyases or carboligases, and the application of enzymes involved in terpene biosynthesis, such as dehydratases, cyclases or transferases [6][8]. An

Lithium phosphonate umpolung catalysts: Do fluoro substituents increase the catalytic activity?

• Anca Gliga,
• Bernd Goldfuss and
• Jörg M. Neudörfl

Beilstein J. Org. Chem. 2011, 7, 1189–1197, doi:10.3762/bjoc.7.138

• ) [31][32]. The energy differences of the terpene-based conformers are between 5.1 and 5.8 kcal/mol [32][33] (B3LYP/6-31++G**:AM1). The conversion of diols 1–5, 7, and 8 to the desired phosphonates can be achieved by twofold addition to phosphorus trichloride and subsequent hydrolysis. Diol 6 could not

Diastereoselective functionalisation of benzo-annulated bicyclic sultams: Application for the synthesis of cis-2,4-diarylpyrrolidines

• Susan Kelleher,
• Pierre-Yves Quesne and
• Paul Evans

Beilstein J. Org. Chem. 2009, 5, No. 69, doi:10.3762/bjoc.5.69

• behaviour for compound 5b in chloroform and toluene appears to be explained based on the polarity of the respective solvents. Toluene with a low dielectric constant favours formation of 13b whereas the more polar chloroform facilitates the rearrangement chemistry via carbocation 22. This type of terpene

Control of asymmetric biaryl conformations with terpenol moieties: Syntheses, structures and energetics of new enantiopure C₂-symmetric diols

• Y. Alpagut,
• B. Goldfuss and
• J.-M. Neudörfl

Beilstein J. Org. Chem. 2008, 4, No. 25, doi:10.3762/bjoc.4.25

• biphenyl axes is controlled by the chiral terpene units and is conformationally surprisingly stable. X-ray analyses reveal M biphenyl conformation for BIMOL and P biphenyl conformation for each of BIVOL, BICOL and BIMEOL. The origins of the conformational biphenyl preferences are confirmed by computational

Allylsilanes in the synthesis of three to seven membered rings: the silylcuprate strategy

• Asunción Barbero,
• Francisco J. Pulido and
• M. Carmen Sañudo

Beilstein J. Org. Chem. 2007, 3, No. 16, doi:10.1186/1860-5397-3-16

• carbocations β to silicon (the so-called β-effect). A unique feature of the reaction is the invariable formation of an exocyclic double bond by loss of the silicon group. The methylenecyclopentanol moiety is present in the skeleton of some naturally occurring terpene families. Recent work has shown that the

An exceptional P-H phosphonite: Biphenyl- 2,2'-bisfenchylchlorophosphite and derived ligands (BIFOPs) in enantioselective copper- catalyzed 1,4-additions

• T. Kop-Weiershausen,
• J. Lex,
• J.-M. Neudörfl and
• B. Goldfuss

Beilstein J. Org. Chem. 2005, 1, No. 6, doi:10.1186/1860-5397-1-6

• recently applied in chiral organolithium reagents [52][53][54][55][56][57][58] and in organozinc [59][60][61][62] as well as in organopalladium catalysts [63][64][65][66][67] to study origins of enantioselectivities in C-C-couplings. The rigid, terpene-based bicyclo[2.2.1]heptane unit enables efficient