Selective deoxygenation of ketones and aldehydes including hindered systems with sodium cyanoborohydride

Hutchins, Robert O.; Milewski, Cynthia A.; Maryanoff, Bruce E.

doi:10.1021/ja00792a033

Cited by 226 publications

(107 citation statements)

References 2 publications

(2 reference statements)

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“…Three hours later, the separation of organic layer over a silica gel column with petroleum ether-acetone (5 : 1) as solvents afforded 23 mg compound 2. The reduction of compound 2 was performed following the procedure described by Hutchins et al 8) Compound 2 (0.05 mmol, 16.5 mg) and p-toluenesulfonylhydrazide (0.07 mmol, 13.0 mg) were dissolved in 5 ml of DMF-sulfolane (1 : 1) containing 0.01 mmol p-toluenesulfonic acid at 100°C. To this mixture was added NaBH 3 CN (0.2 mmol, 12.6 mg).…”

Section: Methodsmentioning

confidence: 99%

Abietane Lactones and Iridoids from Goldfussia yunnanensis

et al. 2007

CHEMICAL & PHARMACEUTICAL BULLETIN

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Section: Methodsmentioning

confidence: 99%

Abietane Lactones and Iridoids from Goldfussia yunnanensis

et al. 2007

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…For example, we were unable to effect the transformation of 9 into the corresponding p-tosylhydrazone, even under quite drastic reaction conditions (43). Furthermore, conversion of 9 into a corresponding en01 phosphate derivative, followed by reduction (12-14) of the latter with lithium in 4We are very grateful to Dr. Kido for his help in carrying out this comparison.…”

Section: Synthesis Of (-)-Cyclocopacamphene (2)mentioning

confidence: 95%

Stereoselective Total Synthesis of Copa and Ylango Sesquiterpenoids: (−)-Copacamphene, (−)-Cyclocopacamphene, (+)-Sativene, (+)-Cyclosativene

Piers¹,

Geraghty²,

Smillie³

et al. 1975

Can. J. Chem.

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EDWARD PIERS, M. BERT GERAGHTY, R. DEAN SMILLIE, and MARCEL SOUCY. Can. J. Chem. 53,2849 (1975).Stereoselective total syntheses of the tricyclic sesquiterpenoids (-)-copacamphene (1) and (+)-sativene (3) and of the related tetracyclic compounds (-)-cyclocopacamphene (2) and (+)-cyclosativene (4) are described. An efficient four-step synthetic sequence was employed to convert the bicyclic dione 5 into the olefinic ketone 8. The latter compound was converted in four steps into the olefinic alcohol 23. Eliminative cyclization of the corresponding tosylate 25 gave (-)-copacamphene (1) in high yield. In similar fashion, (+)-sativene (3) was obtained by cyclization of the olefinic tosylate 42, which in turn was derived via a four-step synthetic sequence from the olefinic ketone 9. Oxidation of the olefinic alcohol 23 afforded the aldehyde 34. Conversion of the latter compound into the p-tosylhydrazone 35, followed by pyrolysis of the corresponding lithium salt 36, gave the pyrazoline 37. Photolysis of 37 afforded, in high yield, (-)-cyclocopacamphene (2). Similarly, (+)-cyclosativene (4) On decrit des syntheses totales et stCreos6lectives des sesquiterpenoides tricycliques (-) copacamphene (1)et (+) sativene (3)et des composCs t6tracycliques (-) cyclocopacamphene (2) et (+) cyclosativtne (4) qui leur sont relies. On a utilise une sequence de synthtse efficace impliquant 4 Btapes pour transformer la dione 5 en cetone non-saturee 8. On a converti ce dernier compose en alcool olefinique 23 en quatre etapes. L'elimination cyclisante du tosylate correspondant 25 donne le (-) copacamphtne (1) avec un bon rendement. D e la mCme maniere, on obtient le (+) sativene (3) par cyclisation du tosylate non-sature 42, qui derive de la cetone non-saturk 9 par I'intermediaire d'une sequence de synthese en 4 etapes. L'oxydation de I'alcool insature 23 fournit l'aldehyde 34 qui est transforme en p-tosylhydrazone 35. La pyrolyse du sel de lithium de cette derniere (36) donne la pyrazoline 37 qui par photolyse conduit, avec un bon rendement, au (-) cyclocopacamphtne (2). On obtient le (+) cyclosativene (4) de la mCme maniere a partir de I'alcool 41 par I'intermediaire de la pyrazoline 46.

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“…Reductive decomposition of tosylhydrazones with LiAlH, and with NaBH, to alkane or alkene was reported by . The reaction has been modified by using NaBH,CN (17) to give reduction products in excellent yields. However, there have been only a few reports (18)(19)(20) on the reaction of tosylhydrazones containing a leaving group on the adjacent carbon.…”

Section: Introductionmentioning

confidence: 99%

Decomposition of tosylhydrazones of benzoin, benzoin acetate, and benzoin benzoate with alkali and metal complex hydrides

Iwadare¹,

Ichinohe²,

Orito³

1996

Can. J. Chem.

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Treatment of tosylhydrazones of benzoin, benzoin acetate, and benzoin benzoate with alkali under protic and aprotic conditions yielded diphenyl acetylene together with desoxybenzoin. An increase in leaving aptitude of the adjacent group enhanced the formation of diphenyl acetylene. By treatment with LiAIH, and with NaBH,, the tosylhydrazones gave stilbenes in good yields. Selective formation of cis-or trnns-stilbene was observed in some cases.

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Selective deoxygenation of ketones and aldehydes including hindered systems with sodium cyanoborohydride

Cited by 226 publications

References 2 publications

Abietane Lactones and Iridoids from Goldfussia yunnanensis

Abietane Lactones and Iridoids from Goldfussia yunnanensis

Stereoselective Total Synthesis of Copa and Ylango Sesquiterpenoids: (−)-Copacamphene, (−)-Cyclocopacamphene, (+)-Sativene, (+)-Cyclosativene

Decomposition of tosylhydrazones of benzoin, benzoin acetate, and benzoin benzoate with alkali and metal complex hydrides

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