A novel synthesis of cis-3,4-disubstituted cyclopentanones

Saito, Kiyoshi; Ishiguro, Y.; Funakoshi, Kazuhisa; Ueno, K.; Shimizu, Hiroshi

doi:10.1016/s0040-4039(01)80074-5

Cited by 58 publications

(14 citation statements)

References 6 publications

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“…2) After that, this hydroacylation of 4-alkenals has been expanded to a catalytic process 3,4) and asymmetric reaction. [5][6][7][8][9][10][11][12][13][14][15][16][17][18] The proposed reaction mechanism is shown in Chart 1. Initially, oxidative addition of the C-H bond of the aldehyde moiety to the rhodium complex occurs to form acylrhodium intermediate i followed by insertion of an alkene moiety to the Rh-H bond to give the 6-membered rhodacycle intermediate ii.…”

Section: Introductionmentioning

confidence: 99%

Development of Novel Cyclizations <i>via</i> Rhodacycle Intermediate and Its Application to Synthetic Organic Chemistry

Oonishi

2015

Chem. Pharm. Bull.

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Novel Rh(I)-catalyzed cyclizations through a different type of rhodacycle intermediate which is formedby hydroacylation of 4,6-dienal or oxidative addition of diene and alkene are described. Hydroacylation of 4,6-dienal afforded various 7-membered rings in good to high yields, while cycloisomerization of diene and alkene provided 5-or 6-membered rings in good yields. On the basis of these studies, we have also succeeded in developing the sequential reaction of hydroacylation followed by cycloisomerization to produce bicyclic compounds in a stereoselective manner and thus this reaction was expanded to the synthesis of epiglobulol. Furthermore, both Rh(I)-catalyzed hydroacylation and cycloisomerization using ionic liquid (IL) as a solvent were investigated and it was found that the IL recovered after the reaction, which contains the Rh(I) catalyst, could be recycled several times without loss of catalytic activity.

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Section: Introductionmentioning

confidence: 99%

Development of Novel Cyclizations <i>via</i> Rhodacycle Intermediate and Its Application to Synthetic Organic Chemistry

Oonishi

2015

Chem. Pharm. Bull.

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“…Initial efforts to recapitulate nepetalactol production using cell-free biosynthesis were prompted by the expensive cost from commercial vendors, the low titers observed in microbial hosts, − and difficulties in implementing synthetic routes. − Reported syntheses suffer from low yields and enantioselectivities, or rely on the costly synthon (−)-citronellol as an enantiopure starting material. − To perform cell-free biosynthesis, geraniol 1 was selected as the starting material because of its high abundance as an essential oil and low cost. Since the plant homologues of G8H are membrane-bound and not suitable for in vitro biocatalysis, a functionally equivalent, soluble bacterial P450 was used.…”

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confidence: 99%

Cell-Free Total Biosynthesis of Plant Terpene Natural Products Using an Orthogonal Cofactor Regeneration System

et al. 2021

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Here we report the one-pot, cell-free enzymatic synthesis of the plant monoterpene nepetalactol starting from the readily available geraniol. A pair of orthogonal cofactor regeneration systems permitted NAD+-dependent geraniol oxidation followed by NADPH-dependent reductive cyclization without isolation of intermediates. The orthogonal cofactor regeneration system maintained a high ratio of NAD+ to NADH and a low ratio of NADP+ to NADPH. The overall reaction contains four biosynthetic enzymes, including a soluble P450, and five accessory and cofactor regeneration enzymes. Furthermore, addition of a NAD+-dependent dehydrogenase to the one-pot mixture led to ∼1 g/L of nepetalactone, the active cat attractant in catnip.

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“…Herein, we document our recent completed total synthesis of 1 that complements Thomson’s approach, wherein a cyclohexanone skeleton has been annulated to a benzofuran ring. As depicted in Scheme , we envisioned the construction of the central cyclohexanone core by a challenging intramolecular alkene hydroacylation reaction. − The intramolecular hydroacylation has been widely used for the annulation of cyclohexanones on the benzene and other heterocyclic rings, and the reports are limited mainly to a monosubstituted olefin . In the present case, the control of the regioselectivity (5- exo vs 6- endo ) and the diastereoselectivity seems to be the key challenge .…”

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confidence: 99%

“…As depicted in Scheme , we envisioned the construction of the central cyclohexanone core by a challenging intramolecular alkene hydroacylation reaction. − The intramolecular hydroacylation has been widely used for the annulation of cyclohexanones on the benzene and other heterocyclic rings, and the reports are limited mainly to a monosubstituted olefin . In the present case, the control of the regioselectivity (5- exo vs 6- endo ) and the diastereoselectivity seems to be the key challenge . The other important retrosynthetic disconnection was the placing of the C(6)-ethyl group as a surrogate for the C(6)-acyl group.…”

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confidence: 99%