β‐Tetralone

Soffer, Milton D.; Bellis, M. P.; Gellerson, Hilda E.; Stewart, Roberta A.

doi:10.1002/0471264180.os032.41

Cited by 7 publications

(12 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The same adduct resulted from quenching the ozonolysis mixture of 9 with excess bisulfite solution, where the sulfite is responsible for both reductive cleavage of ozonide and addition to the carbonyl group. [42] The usual recuperation of aldehydes from bisulfite adducts with aqueous acid or base[43] failed with 22 , which only returned low amounts of impure 5 when stirred in aqueous–organic two‐phase systems with base (see Table S‐1 ). Stirring of 22 in a pH 4 buffer with extraction into t BuOMe gave a low quantity of pure 5 , however.…”

Section: Resultsmentioning

confidence: 99%

Configurational Assignment of ‘Cryptochiral’ 10‐Hydroxystearic Acid Through an Asymmetric Catalytic Synthesis

Brunner

Hintermann

2016

Helvetica Chimica Acta

View full text Add to dashboard Cite

An asymmetric catalytic total synthesis of (S)‐10‐hydroxystearic acid (1) for comparison of its absolute configuration to that of samples obtained by fermentative hydration of oleic acid is reported. The synthesis involves two catalytic key‐steps, namely Ru‐catalyzed anti‐Markovnikov hydration of 9‐decynoic acid (7) to 10‐oxodecanoic acid (5), followed by titanium‐mediated asymmetric catalytic addition of dioctylzinc (25) to 5 in presence of the chiral ligand N,N’‐((1R,2R)‐cyclohexane‐1,2‐diyl)bis(1,1,1‐trifluoromethanesulfonamide) (6). The synthesis is short and efficient and avoids use of protecting groups. Ozonolysis of 10‐undecynoic acid (9) to 5 provides an alternative entry point into the synthetic route. The double dehydrobromination of (ω,ω‐1)‐dibromoalkanoic acids to ω‐alkynoic acids under a variety of conditions was investigated with 10,11‐dibromoundecanoic acid (11) as model substrate and using qNMR to quantify all reaction products. The synthetic approaches presented here have the potential to be generalized to the asymmetric catalytic synthesis of a variety of n‐hydroxy‐fatty acids.

show abstract

Section: Resultsmentioning

confidence: 99%

Configurational Assignment of ‘Cryptochiral’ 10‐Hydroxystearic Acid Through an Asymmetric Catalytic Synthesis

Brunner

Hintermann

2016

Helvetica Chimica Acta

View full text Add to dashboard Cite

show abstract

“…Among the known synthetic approaches to 2-tetralones, we decided to use the Na/EtOH reduction of 2-methoxynaphthalenes, 13 initially described by Cornforth et al, 14 which had been successfully applied by us for the synthesis of differently substituted 8-alkyl-2-tetralones. 15 Birch reductions 16 of naphthalenes bearing electron-releasing substituents at the C-1 are known to occur at the unsubstituted aromatic ring, whereas electron-withdrawing groups at C-1 direct the reduction to the same ring.…”

Section: Methodsmentioning

confidence: 99%

“…Compound 1c:1 H NMR: d = 2.49 (m, 2 H), 3.12 (m, 2 H), 3.28 and 3.48 (AB system, 2 H, J = 19.6 Hz), 3.72 (s, 3 H), 3.84 (s, 3 H), 6.52 (t, 1 H, J = 2.3 Hz), 6.55 (d, 1 H, J = 2.5 Hz), 7.04 (d, 1 H, J = 8.0 Hz), 3.23 and 3.37 (AB system, 2 H, J = 19.6 Hz), 7.02-7.46 (m, 7 H) 13. C NMR: d = 23.1, 24.6, 28.8, 29.9, 38.1, 42.9, 125.5, 125.6, 126.1, 126.6, 128.0, 128.3, 129.3, 131.4, 136.8, 138.6, 141.1, 146.5, 210.6.…”

mentioning

confidence: 99%

Ring Selectivity in the Na/EtOH Reduction of 1-Aryl-7-methoxynaphthalenes

Carreño¹,

González-López²,

Latorre³

et al. 2005

Synlett

View full text Add to dashboard Cite

Na/EtOH reduction of 1-aryl-7-methoxynaphthalenes occurred preferentially at the A-ring when no substituents were present at the ortho-positions of the aryl group (up to 100% selectivity), to afford 1-aryl-7-methoxy-1,2,3,4-tetrahydronaphthalenes. Ortho-substitution of the 1-aryl moiety favored B-ring reduction (up to 85:15 selectivity) giving rise, after acidic hydrolysis of the vinyl ether intermediate, to the corresponding 8-aryl-2-tetralones.Selective reduction of polyaromatic compounds has received little attention despite the fact there is much interest in a controlled access to differently substituted hydroaromatic derivatives. The few studies published so far deal with metal/ammonia reduction of terphenyls 1 and naphthyl or dinaphthylbenzenes. 2 These studies revealed that the ratio of central to outer ring reduction products depended on the particular metal used in the case of p-terphenyls, whereas m-and o-terphenyls gave only central ring reduction. Moreover, reduction of 1-and 2-phenylnaphthalene never occurred at the phenyl ring. 2a The controlled reduction of substituted 2-methoxy naphthalene derivatives is of great interest since the resulting vinyl ether can be easily hydrolyzed to 2-tetralones. Such compounds have been frequently used in organic synthesis due to their high versatility and suitability as precursors of a wide range of synthetic and natural products and their derivatives, 3 heterocycles, 4 and pharmaceuticals 5 showing biological activities and other useful properties. However, unlike their congeners the 1-tetralones, which are inexpensive, easily prepared, and commercially available substances, 2-tetralones are often very expensive and much more difficult to synthesize.The most common methods for the preparation of 2-tetralones 6 involves 1,2-transposition of the carbonyl group of 1-tetralones, 7 reduction of substituted 2-methoxy-naphthalenes followed by hydrolysis, 8 cyclization of diazoketones, 9 and the Friedel-Crafts reaction of aromatic acyl chlorides with olefins. 10In connection with a program devoted to the synthesis of polyaromatic compounds such as helicenes, 11 we required several 8-aryl-2-tetralones (1; Scheme 1) bearing different substituents at the aryl moiety. To the best of our knowledge, the synthesis of 8-aryl-2-tetralones has been addressed only using the carbanion-induced condensation of differently substituted 2H-pyran-2-ones with a 1,4-cyclohexanedione monoketal, 12 however, the synthesis of these starting materials is not easy.Scheme 1 Retrosynthesis to 8-aryl-2-tetralones 1.Among the known synthetic approaches to 2-tetralones, we decided to use the Na/EtOH reduction of 2-methoxynaphthalenes, 13 initially described by Cornforth et al., 14 which had been successfully applied by us for the synthesis of differently substituted 8-alkyl-2-tetralones. 15 Birch reductions 16 of naphthalenes bearing electron-releasing substituents at the C-1 are known to occur at the unsubstituted aromatic ring, whereas electron-withdrawing groups at C-1 direct the reduction to the s...

show abstract

“…Unhindered aldehydes readily react with sodium bisulfite to form addition products which are highly insoluble in organics . The reaction is reversible on treatment with either acid or base and is useful for separation of aldehydes from other organic-soluble compounds.…”

Section: Process Developmentmentioning

confidence: 99%

Development of a Practical Biocatalytic Process for (R)-2-Methylpentanol

Gooding¹,

Voladri²,

Bautista³

et al. 2009

Org. Process Res. Dev.

View full text Add to dashboard Cite

(R)-2-Methylpentanol is an important chiral intermediate for the synthesis of certain medicinally important compounds, natural products, and liquid crystals. Here we describe the development of a practical kinetic resolution utilizing an enantiospecific biocatalytic reduction of racemic 2-methylvaleraldehyde. The process utilizes an evolved ketoreductase enzyme to selectively reduce the (R)-enantiomer of racemic 2-methylvaleraldehyde to the desired product with high volumetric productivity. A scaleable method for separating the desired product from the off-enantiomer of the starting material is also described. The process is cost-effective, green, and amenable to manufacturing scale.

show abstract

β‐Tetralone

Abstract: β‐Tetralone intermediate: β‐tetralone bisulfite product: β‐tetralone

Cited by 7 publications

References 4 publications

Configurational Assignment of ‘Cryptochiral’ 10‐Hydroxystearic Acid Through an Asymmetric Catalytic Synthesis

Configurational Assignment of ‘Cryptochiral’ 10‐Hydroxystearic Acid Through an Asymmetric Catalytic Synthesis

Ring Selectivity in the Na/EtOH Reduction of 1-Aryl-7-methoxynaphthalenes

Development of a Practical Biocatalytic Process for (R)-2-Methylpentanol

Contact Info

Product

Resources

About