Synthesis oftrans- and cis-α-damascone

1978 ◽  
Vol 56 (10) ◽  
pp. 1368-1371 ◽  
Author(s):  
Hsing-Jang Liu ◽  
Hing-Kwok Hung ◽  
George L. Mhehe ◽  
M. L. Duarte Weinberg
Keyword(s):  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Complete Recovery ◽  
Lithium Aluminum ◽  
Magnesium Bromide ◽  
Keto Ester ◽  
Keto Esters ◽  
Hydride Reduction ◽  
Cis And Trans ◽  
Cis Isomer

Se lective thioketalization of a mixture of keto esters 5 and 6 resulted in the exclusive formation of thioketal 7 and complete recovery of keto ester 6. Lithium aluminum hydride reduction of thioketal 7 followed by Moffatt oxidation of the resulting alcohol 8 gave aldehyde 10 which on treatment with a mixture of cis- and trans-1-propenyl magnesium bromide afforded trans- alcohol 11 and its cis isomer 12. Manganese dioxide oxidation of alcohol 11 followed by desulfurization gave trans α-damascone (3). Similarly, alcohol 12 was converted to cis-α-damascone (4).

Sur la réduction de polyméthyldihydro-2,3 phénalènones-1 par l'hydrure de lithium et d'aluminium

1974 ◽  
Vol 52 (17) ◽  
pp. 3106-3112 ◽  
Author(s):  
E. Costakis ◽  
P. Canonne ◽  
R. St-Jean
Keyword(s):  
Trans Isomer ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Considerable Extent ◽  
Lithium Aluminum ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
Cis Isomer ◽  
Steric Constraints

The reduction of some polymethyl-2,3-dihydro phenalen-1-ones by lithium aluminum hydride yields a mixture of cis and trans isomers; the percentage of each isomer depends to a considerable extent on its structure. Indeed, for some, the trans isomer predominates while for others the cis isomer is obtained in up to 88% yields. Moreover, in the particular case in which the trans isomer is formed in low yields, its preferred conformation is trans diaxial.The steric constraints which render certain transition states unfavourable during the attack of the hydride are discussed with the aid of spectroscopic data on the alcohols obtained. [Journal translation]

The Chemistry of Sulfur Curing. IV. Effects of Organic Accelerators on the Reaction of Cyclohexene with Sulfur

1968 ◽  
Vol 41 (5) ◽  
pp. 1339-1347 ◽  
Author(s):  
James R. Wolfe
Keyword(s):  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Major Product ◽  
Lithium Aluminum ◽  
Radical Mechanism ◽  
Secondary Products ◽  
Tetramethylthiuram Disulfide ◽  
Hydride Reduction ◽  
Free Radical Mechanism ◽  
Cis And Trans

Abstract Cyclohexene reacts with sulfur at 140° in the presence of zinc dimethyldithio-carbamate, tetramethylthiuram monosulfide, or tetramethylthiuram disulfide, to produce 2-cyclohexene-1-thiol as the major product after lithium aluminum hydride reduction of the polysulfide compounds. Secondary products are cis- and trans-1, 2-eyclohexanedithiol and cyclohexanethiol. Zinc dimethyldithiocarbamate is postulated to promote the reaction via an ionic mechanism as it causes more trans than cis-1, 2-cyclohexanedithiol to be formed. Tetramethylthiuram monosulfide and disulfide are postulated to promote the reaction via a free radical mechanism as they cause more cis- than trans-1, 2-cyclohexanedithiol to be formed.

Free Radical Substitution Reactions of Sulfur Monochloride. A Limited Synthesis of Mercaptans

1973 ◽  
Vol 51 (20) ◽  
pp. 3366-3372 ◽  
Author(s):  
Dennis D. Tanner ◽  
Brian G. Brownlee
Keyword(s):  
Free Radical ◽  
Lithium Aluminum Hydride ◽  
Elemental Sulfur ◽  
Aluminum Hydride ◽  
Lithium Aluminum ◽  
Substitution Reactions ◽  
Sulfur Monochloride ◽  
Hydride Reduction ◽  
Abstraction Reaction ◽  
Radical Substitution

The photolysis of sulfur monochloride with a series of saturated aliphatic hydrocarbons yielded alkyl chlorides, di- and polysulfides, hydrogen chloride, and elemental sulfur. The free radical substitution reactions leading to the production of alkyl chloride and the di- and polysulfides were shown to proceed via a chlorine atom abstraction reaction. The major products, the di- and polysulfides could be transformed quantitatively, by lithium aluminum hydride reduction into their corresponding mercaptans. The reaction describes a simple free radical route to the synthesis of a variety of alkyl mercaptans.

Preparation and Spectral Analysis of 3,3',4,4'-Tetrachloroazobenzene and the Corresponding Azoxy and Hydrazo Analogs

1979 ◽  
Vol 62 (4) ◽  
pp. 746-750
Author(s):  
M T Stephen Hsia ◽  
Charles F Burant
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Chromatographic Method ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Lithium Aluminum ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Hydride Reduction ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract An efficient preparation was developed for 3,3',4,4'-tetrachloroazobenzene and the corresponding azoxy and hydrazo derivatives, based on the lithium aluminum hydride reduction of 3,4-dichIoronitrobenzene. Batches were analyzed for purity by using a reverse phase high pressure liquid chromatographic method. All 3 compounds can be synthesized in gram quantities with 97–99% purity. Detailed mass, infrared, and nuclear magnetic resonance spectral analyses are presented.

Sign in / Sign up

Export Citation Format

Share Document