Selective allylic hydroxylation of acyclic terpenoids by CYP154E1 from Thermobifida fusca YX

• Anna M. Bogazkaya,
• Clemens J. von Bühler,
• Sebastian Kriening,
• Alexandrine Busch,
• Alexander Seifert,
• Jürgen Pleiss,
• Sabine Laschat and
• Vlada B. Urlacher

Beilstein J. Org. Chem. 2014, 10, 1347–1353, doi:10.3762/bjoc.10.137

• Supporting Information File 1). There is no literature procedure for the synthesis of alcohol derivatives of geraniol (1) or nerol (2) by direct allylic oxidation. However, various conditions have been reported for geranyl acetate [32][33][34]. Following a modified procedure by Li [33], geranyl acetate ((E

• into neryl acetate ((Z)-19) in 87%, followed by allylic oxidation [38], to provide enal (Z)-20 and allylic alcohol (Z)-21 in 14% and 41% yield, respectively. Saponification of 8-hydroxyneryl acetate ((Z)-21) under the above mentioned conditions gave 8-hydroxynerol (4) in 73% yield (Scheme 2). Following

• ], modified Sharpless conditions [36] for the allylic oxidation of geranylacetone (9) were used. Purification of the crude product by chromatography yielded the enal (E)-22 (9%) and a 11:89 mixture of the alcohols 7-hydroxygeranylacetone (11) and 11-hydroxygeranylacetone (13) in 34% yield and 11% of starting

Synthesis of complex intermediates for the study of a dehydratase from borrelidin biosynthesis

• Frank Hahn,
• Nadine Kandziora,
• Steffen Friedrich and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2014, 10, 634–640, doi:10.3762/bjoc.10.55

• unconventional biosynthesis mechanisms [5][6]. The carbonitrile for example is probably formed by allylic oxidation of the 12-methyl group in 12-desnitrile-12-methylborrelidin to the corresponding aldehyde and transamination to the amine followed by oxidation [6]. In the course of our studies on borrelidin

Elucidation of the regio- and chemoselectivity of enzymatic allylic oxidations with Pleurotus sapidus – conversion of selected spirocyclic terpenoids and computational analysis

• Verena Weidmann,
• Mathias Schaffrath,
• Holger Zorn,
• Julia Rehbein and
• Wolfgang Maison

Beilstein J. Org. Chem. 2013, 9, 2233–2241, doi:10.3762/bjoc.9.262

• developed. The oxidations follow a radical mechanism and the regioselectivity of the reaction is mainly determined by bond-dissociation energies of the available allylic CH-bonds and steric accessibility of the oxidation site. Keywords: allylic oxidation; CH-activation; chiral separation; enones; flavors

• addition, metal-free and biocatalytic methods have been reported [5]. Several of these biocatalytic protocols have been applied to the synthesis of fine chemicals [20][21][22], drugs [23], and food ingredients [24][25][26]. A particularly interesting biocatalytic system for allylic oxidation is the edible

• responsible for the allylic oxidation of valencene to nootkatone, and the same enzyme oxidizes unsaturated fatty acids [29][31]. It is thus likely that this dioxygenase is the major oxidant in other allylic oxidations with PSA-lyophilisate, too. However, since the lyophilisate is a mixture of enzymes

The chemistry of isoindole natural products

• Klaus Speck and
• Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

• diastereoselective allylic oxidation to provide (±)-nominine (225). In 2008, the same group reported the first total synthesis of (+)-nominine by introducing the desired stereochemical information to the nitrile 235 [179]. Conclusion The outlined syntheses of natural products containing the uncommon isoindole

Synthesis of the tetracyclic core of Illicium sesquiterpenes using an organocatalyzed asymmetric Robinson annulation

• Lynnie Trzoss,
• Jing Xu,
• Michelle H. Lacoske and
• Emmanuel A. Theodorakis

Beilstein J. Org. Chem. 2013, 9, 1135–1140, doi:10.3762/bjoc.9.126

• the way for a diversity-oriented synthesis. For example, a Mn(III) promoted C-2 allylic oxidation [24][101][102] would provide a C-2 oxygenated functionality. Similarly, C-10 α-substitution would provide a large diversity of neurotrophic analogues based on our recent findings [26]. Conclusion We

Synthesis and characterization of Sant-75 derivatives as Hedgehog-pathway inhibitors

• Chao Che,
• Song Li,
• Bo Yang,
• Shengchang Xin,
• Zhixiong Yu,
• Taofeng Shao,
• Chuanye Tao,
• Shuo Lin and
• Zhen Yang

Beilstein J. Org. Chem. 2012, 8, 841–849, doi:10.3762/bjoc.8.94

• the presence of catalytic NaOMe, followed by treatment with NH4Cl. Then, condensation of 13 with acetylacetaldehyde dimethyl acetal in 1,4-dioxane afforded 6-methyl-2-(4-pyridinyl)pyrimidine 14 in 62% yield [47]. Consequent allylic oxidation of 14 with selenium dioxide gave 11e in moderate yield