scholarly journals Transformation of 2,3-dibenzylbutyrolactone lignans containing a secondary hydroxyl group to phenyltetralin lignans and their reduction products with lithium aluminum hydride.

1981 ◽  
Vol 29 (7) ◽  
pp. 2082-2085 ◽  
Author(s):  
SANSEI NISHIBE ◽  
HIROKI TSUKAMOTO ◽  
SUEO HISADA ◽  
SAKAE YAMANOUCHI ◽  
MICHIO TAKIDO
Keyword(s):  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Hydroxyl Group ◽  
Lithium Aluminum ◽  
Secondary Hydroxyl

PITHECOLOBINE, THE ALKALOID OF PITHECOLOBIUMSAMAN BENTH. I

1952 ◽  
Vol 30 (10) ◽  
pp. 761-772 ◽  
Author(s):  
K. Wiesner ◽  
D. M. MacDonald ◽  
Z. Valenta ◽  
R. Armstrong
Keyword(s):  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Ultraviolet Spectrum ◽  
Hydroxyl Group ◽  
Lithium Aluminum ◽  
Amino Groups ◽  
Saturated Compound ◽  
Secondary Amino ◽  
Trimethyl Amine ◽  
Methylene Group

Pithecolobine, C22H46N4O2, has a lactam group, one primary and two secondary amino groups, and a hydroxyl group. Lithium aluminum hydride converts it into a monocyclic saturated compound, desoxypithecolobine, C22H48N4. Hofmann degradation of this compound gives tetramethylputrescine, trimethyl amine, a doubly unsaturated base C16H31N with a terminal methylene group, and a base C16H34N2. Heating with selenium yields a hydrocarbon, C12;H24–26, with a sequence of six or more CH2 groups. A crystalline oxygen-free compound with two nitrogens (m.p.94 °C.) is also obtained, the ultraviolet spectrum of which is almost identical with aminopyridine.

THE PAPILIONACEOUS ALKALOIDS: XIX. THE STRUCTURE OF LUPANOLINE

1953 ◽  
Vol 31 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Barry P. Moore ◽  
Léo Marion
Keyword(s):  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Hydroxyl Group ◽  
Lithium Aluminum ◽  
Direct Oxidation

Lupanoline which contains both a carbonyl and a hydroxyl group was reduced by lithium aluminum hydride to β-isosparteine. The identity of β-isosparteine was established by its conversion into sparteine by dehydrogenation and subsequent rehydrogenation. Attempts to acylate lupanoline resulted in the formation of anhydrolupanoline which was hydrogenated to dihydroanhydrolupanoline, a compound also obtained by the direct oxidation of β-isosparteine.It is concluded that lupanoline is 2-hydroxy-17-oxo-β-isosparteine.

Lithium Aluminum Hydride Reductive Rearrangement of Allylic Acetals to Vinyl Ethers: A Synthesis of 3-Deoxy Glycals

1975 ◽  
Vol 53 (13) ◽  
pp. 2005-2016 ◽  
Author(s):  
Bert Fraser-Reid ◽  
Steve Y-K. Tam ◽  
Bruno Radatus
Keyword(s):  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Hydroxyl Group ◽  
Lithium Aluminum ◽  
Allylic Alcohols ◽  
Vinyl Ethers ◽  
Hydride Ion ◽  
Lithium Aluminium ◽  
Leaving Group ◽  
Ethereal Oxygen

Carbohydrate allylic acetals (hex-2-enopyranosides) are reductively rearranged to vinyl ethers (3-deoxy glycals) by treatment with lithium aluminium hydride in refluxing ethereal solvents. Under similar conditions, some allylic alcohols are also reductively rearranged to olefins, although the reaction appears to be confined to carbohydrate substrates since the reaction fails with typical carbocyclic allylic alcohols.The results are rationalized by postulating the intermediacy of an oxygen–alane complex, this being formed more readily in the case of an hydroxyl (or ester) rather than an ethereal oxygen. An axial oxygen permits easier achievement of the reactive transition state than an equatorial oxygen. The complex normally leads to an SN2' reductive rearrangement in which the entering hydride and departing oxygen are syn-related. Alternatively, and particularly when the double bond is flanked by an hydroxyl group at one allylic position and a leaving group at the other, an abnormal SN2′ process may occur so that the hydride ion is delivered vicinal and cis to the hydroxyl group, with ejection of the leaving group. The process is at all times stereospecific but not always regiospecific.

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