Reduction of aldehydes and ketones.Patent US4877909
Abstract
Aldehydes and ketones were reduced by treating with alcs. in the presence of zirconium oxide hydrate. Thus, PhCOPh was refluxed with iso-PrOH in the presence of zirconium oxide hydrate obtained from ZrOCl2.8H2O to give 98% PhCHOHPh.
The catalytic reduction of aldehydes and ketones with 2-propanol over hydrous zirconium oxide. Shibagaki, Makoto; Takahashi, Kyoko; Matsushita, Hajime.
Bull. Chem. Soc. Jpn. (1988) 61(9), 3283-8. Journal in English.
Enantioselective addition of diethylzinc to benzaldehyde catalyzed by a small amount of chiral 2-amino-1-alcoholsTetrahedron Letters, (1984) 25(26), 2823-2824
Nobuki Oguni, and Takao Omi
Procedure
To a stirred solution of benzaldehyde(9 mmol) and chiral 2-amino-1-alcohol(O.18 mmol) in toluene (15 ml) was added diethylzinc(9 mmol) under argon atmosphere, and the whole mixture was stirred at 20°C for 48 h. Then dilute HCl was added dropwise to the reaction mixture at 0°C and the organic layer was separated, dried over Na2S04, and concentrated under reduced pressure. The resulting 1-phenylpropan-l-ol was distilled under reduced pressure.
Results
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Catalyst Temperature(C) Time(h) Yield(%)
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(S)-1-phenylethylamine 20 48 95
(S)-1-phenylpropan-1-ol 30 48 56
(S)-alaninol 20 41 97
(S)-valinol 20 44 95
(S)-leucinol 20 43 96
(S)-phenylalaninol 30 41 98
(S)-prolinol 30 42 100
Enantioselective addition of diethylzinc to benzaldehyde in the presence of ephedrine derivatives.Chaloner, Penny A.; Perera, S. A. Renuka.
Tetrahedron Lett. (1987), 28(26), 3013-14.
Abstract
Et2Zn adds to RC6H4CHO (R = H, m- and p-Me and -CF3, p-Br, m-Cl) in the presence of ephedrine and its N-alkyl derivs., to give 40-72% RC6H4CHEtOH in 52-80% enantiomeric excess at room temp. without special precautions.
This is similar to the above article except they don't give exact details of the reaction. The chiral catalyst is ephedrine, yeild 60%. With N-isopropylephedrine the yeild is 72%.
Enantioselective reaction of diethylzinc with arenecarboxaldehydes in the presence of ephedrine derivatives. Chaloner, Penny A.; Langadianou, Eugenia; Perera, S. A. Renuka.
J. Chem. Soc., Perkin Trans. 1 (1991) (11), 2731-5.
Abstract
The stereoselective alkylation by diethylzinc of aryl aldehydes was catalyzed by N-alkylephedrines to give 1-aryl-1-propanols. The (1R,2S)-N-isopropylephedrine-catalyzed alkylation of 4-methylbenzaldehyde with diethylzinc gave (R)-1-(4-methylphenyl)-1-propanol in 73% yield in 73.7% enantiomeric excess. The (1R,2S)-norephedrine-catalyzed alkylation of benzaldehyde with diethylzinc gave (R)-a-ethylbenzenemethanol in 99% yield in 55.8% enantiomeric excess. The reaction mechanism was discussed.
Using the procedure in Post 292212
(foxy2: "1-phenyl-2-propanol synthesis", Novel Discourse)First Grignard - PhMgBr
Second Grignard - EtMgCl
Yeild 1-phenyl-2-propanol = 84%
Methylation-hydroxylation of certain aromatic unsaturated compounds.Patent US3806548
Synth from styrene, peracetic acid and UV light.
Full Text:
Post 481881
(Aurelius: "US pat 3806548 1-phenyl-1-propanol from styrene", Chemistry Discourse)Preparation of 1-phenylpropanol as choleretic agent.Oda, Shingo; Aoyama, Hiroshi.
Jpn. Kokai Tokkyo Koho (1987), JP 62169739 A2 19870725 Patent In Japanese.
Abstract
EtCH(OH)Ph (I), useful as chloretic agent (no data), is simultaneously prepd. with styrene oxide (II). A 10% soln. of Fe(NO3)3 in HOAc was added to 0.5 mol styrene at 55°, followed by 1.0 mol 30% MeCO2OH, and the mixt. kept 10 min at 55° to give I 22.6, II 53.1, and PhCH2CHO 0.3%, vs. 30.1, 28.0, and 12.3%, resp., at 85°.
Reduction of aldehydes and ketones using sodium formate in 1-methyl-2-pyrrolidinone. J. Org. Chem. (1981), 46(16), 3367-9.
Abstract
Several representative aldehydes and ketones were reduced to the corresponding alcs. using HCO2Na in refluxing 1-methyl-2-pyrrolidinone contg. potassium phosphate monobasic as a buffer. A competitive expt. involving 4-MeC6H4CHO and MeCOCH2CH2Ph was conducted to show that reaction conditions could be developed for chemoselective redn. of aldehydes.
Reduction of aldehydes and ketones to alcohols with hydrous zirconium oxide and 2-propanol.Matsushita, Hajime; Ishiguro, Shigeo; Ichinose, Hiroshi; Izumi, Akira; Mizusaki, Shigenobu.
Chem. Lett. (1985), (6), 731-4.
Abstract
RCHO (R = EtCHMe, pentyl, nonyl, Ph, 4-Me2CHC6H4CH2CHMe, Pr, Me2CH), R1COR2 [R1 = Ph, octyl, heptyl, Et; R2 = Me, Et, Ph; R1R2 = (CH2)5, CH2CH2CHMe, CH:CHCOCH:CH] and camphor were efficiently reduced with Me2CHOH in the presence of Zr(OH)2O. RCHOH and R1R2CHOH were easily isolated in the pure state by filtering off the Zr(OH)2O followed by solvent evapn.
Reduction with Raney nickel in aqueous sulfuric acid.Okimoto, Mitsuhiro; Chiba, Toshiro; Takata, Yoshiyuki.
Nippon Kagaku Kaishi (1985), (9), 1671-5.
ISSN: 0369-4577. Journal in Japanese. CAN 105:42295
Abstract
Lab. scale redn. was achieved by adding sulfuric acid to the mixt. of substrate and Ra/Ni either in aq. soln. or aq. methanol soln. at room temp. Ketones and aldehydes were reduced to the corresponding alc. in good yields. By use of an excess Ra/Ni, the redn. of ketones contg. a carbonyl group directly attached to an arom. nucleus gave the corresponding hydrocarbons. Olefinic double bonds were likewise readily hydrogenated under the same conditions. The selective hydrogenation of unsatd. ketones to the satd. ketones was possible with adjustment of the amt. of Ra/Ni used.
A new type of complex reagent, tetraalkyllead-titanium tetrachloride. Yamamoto, Yoshinori; Yamada, Junichi; Asano, Tetsuya.
Tetrahedron (1992), 48(27), 5587-96.
A new type of stable, storable, and selective alkylating reagent, tetraalkyllead.Yamamoto, Yoshinori; Yamada, Junichi.
J. Am. Chem. Soc. (1987), 109(14), 4395-6.
Abstract
Tetraalkylleads (R4Pb) reacted quite smoothly with aldehydes R1CHO in the presence of Lewis acids such as TiCl4 and BF3 to produce RR1CHOH in high to good yields. For example, Et4Pb and Bu4Pb reacted with BzH, cyclohexanecarboxaldehyde, and octanal in the presence of TiCl4. Even tetracyclohexyllead gave the alkylation product. The reagent system, R4Pb/TiCl4, exhibited high chemoselectivity; only aldehydes underwent the alkylation in the presence of ketones. Further, the new reagent exhibited high 1,2- and 1,3-asym. induction. 2-Phenylpropanal produced the Cram isomer in a ratio of 93:7 upon treatment with Et4Pb/TiCl4. 3-(Benzyloxy)butanal gave the chelation product in a ratio of 91:9 upon treatment with Bu4Pb/TiCl4.
Alkylation of carbonyl compounds with alkylleads.Patent JP63215644
Abstract
Carbonyl compds. are alkylated with alkylleads in the presence of Lewis acids. The alkylleads may be R4Pb (R = C1-10 alkyl, C5-12 cycloalkyl). A CH2Cl2 soln. of TiCl4 and a CH2Cl2 soln. of Et4Pb were successively added to PhCHO in CH2Cl2 at -78° and the reaction mixt. was gradually heated to -30° to give 96% PhCH(Et)OH.
A new convenient reduction of aralkyl ketones to alcohols using Raney nickel-ammonium formate. Chen, Fener; Zhang, Heng; Yuan, Wei; Zhang, Wenwen.
Synth. Commun. (1991), 21(1), 107-9.
Abstract
Redn. of RCOR1 (R = Ph, substituted Ph; R1 = Me, Et) with Raney Ni and ammonium formate in MeOH at room temp. gave 90-92% RCH(OH)R1.
Catalytic hydrogen transfer over magnesia. XIII. Liquid phase reduction of substituted 1-phenyl-1-alkanones by 2-octanol. Glinski, M.
Polish Journal of Chemistry (2000), 74(
, 1207-1209. ISSN: 0137-5083. Journal in English. CAN 133:281301
Abstract
1-Phenyl-1-alkanones were reduced by 2-octanol in the liq. phase in presence of MgO as a catalyst to 1-phenyl-1-alkanols.
Catalytic hydrogen transfer over magnesia. XII. Reduction of metameric 1-phenyl-X-butanones (X = 1, 2 or 3) by 2-propanol. Glinski, M.; Radomski, P.
Pol. J. Chem. (1999), 73(7), 1233-1235.
Abstract
Hydrogen transfer from 2-propanol to 1-phenyl-1-butanone, 1-phenyl-2-butanone, or 2-phenyl-2-butanone in the presence of magnesium oxide (MgO) catalyst gave the corresponding alcs., i.e., 1-phenyl-2-butanol, 1-phenyl-2-butanol and 4-phenyl-2-butanol, resp.
Diisopropoxyaluminum trifluoroacetate. A new off-the-shelf metal alkoxide-type reducing agent for reduction of aldehydes and ketones. Akamanchi, K. G.; Varalakshmy, N. R.; Chaudari, B. A.
Synlett (1997), (4), 371-372.
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