19-Hydroxy Steroids. II. The Synthesis of 3 β,5,19-Trihydroxy-5 β-cholestane

1971 ◽  
Vol 49 (19) ◽  
pp. 3185-3191 ◽  
Author(s):  
Peter Morand ◽  
Morris Kaufman
Keyword(s):  
Double Bond ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Lithium Aluminum ◽  
Chemical Evidence

Chemical evidence is presented in support of the structures assigned to the isomeric epoxides 4a and 5a obtained by peracid oxidation of the double bond in 3β-acetoxycholest-5-en-19-ol (2a). Reduction of 3β-acetoxy-5,6α-oxido-5α-cholestan-19-ol (4a) with lithium aluminum hydride leads exclusively to the C-5 alcohol while reduction of 3β-acetoxy-5,6β-oxido-5β-cholestan-19-ol (5a) with the same hydride results in the isolation of the C-5 and -6 alcohols in a ratio of 1:5. When an attempt was made to reduce the 5β,6β-epoxide 5a with lithium trimethoxyaluminohydride a rearrangement occurred. A structure is postulated for the compound isolated and a mechanism for its formation is discussed.

THE STRUCTURE OF MITRAPHYLLINE

1958 ◽  
Vol 36 (7) ◽  
pp. 1031-1038 ◽  
Author(s):  
J. C. Seaton ◽  
R. Tondeur ◽  
Léo Marion
Keyword(s):  
Double Bond ◽  
Experimental Evidence ◽  
Aromatic Amine ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Mineral Acid ◽  
Lithium Aluminum ◽  
Spectroscopic Evidence ◽  
Mild Conditions ◽  
Total Structure

Mitraphylline (C21H24O4N2) contains a carbomethoxyl group, and on hydrolysis gives rise to mitraphyllic acid. Spectroscopic evidence shows that the alkaloid contains two chromophores, one characteristic of an oxindole and one corresponding to the grouping CH3OOC—Ć==CH.OR. On treatment with dilute mineral acid the alkaloid gives rise to mitraphyllal (C19H24O3N2), which is a hemiacetal that no longer contains the isolated double bond and the carbomethoxyl group originally present in the alkaloid. Reduction of mitraphyllal by the Wolff–Kishner reaction gives mitraphyllane (C19H26O2N2). The dehydrogenation of mitraphyllal produced 3,4-diethylpyridine and 3-ethyloxindole. The action of lithium aluminum hydride on mitraphylline under mild conditions gave rise to mitraphyllol by reduction of the carbomethoxyl group, and under more vigorous conditions to dihydrodesoxy-mitraphyllol by reduction of the oxindole carbonyl as well. This last product has the properties of an aromatic amine. On the basis of the new experimental evidence, a total structure of mitraphylline is derived.

scholarly journals Pyranosiduloses. II. The synthesis and properties of some alkyl 2,3-dideoxy-2-enopyranosid-4-uloses

1970 ◽  
Vol 48 (18) ◽  
pp. 2877-2884 ◽  
Author(s):  
Bert Fraser–Reid ◽  
Angus McLean ◽  
E. W. Usherwood ◽  
Mark Yunker
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Double Bond ◽  
Magnetic Resonance ◽  
Boron Trifluoride ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Lithium Aluminum ◽  
Crystalline Substance ◽  
Unsaturated Ketones ◽  
Olefinic Double Bond

Ethyl 2,3-dideoxy-α-D-erythro-hex-2-enopyranoside (9a) an accessible and highly crystalline substance is selectively oxidized at the allylic position to ethyl 2,3-dideoxy-α-D-glycero-hex-2-enopyranosid-4-ulose (10a) in 80% yield. This hydroxyketone can be benzoylated, acetylated, and tosylated, and the resulting esters are all highly crystalline, as is the parent ketone. 3,4-Di-O-acetyl-D-xylal reacts with ethanol under boron trifluoride catalysis to give the anomeric mixture of ethyl 4-O-acetyl 2,3-dideoxy-D-glycero-pent-2-enopyranosides which may be separated after deacetylation. The deacetylated α-D anomer (14α) is readily oxidized by manganese dioxide to give an ethyl 2,3-dideoxy pent-2-enopyranosid-4-ulose (6-ethoxy-2,6-dihydropyran-3-one) (12); however, the corresponding β-D (14β) anomer resists oxidation. All of these ketones display a diagnostic nuclear magnetic resonance pattern consisting of clean doublets for H-1 and -3, and a doublet of doublets for H-2. Reduction of 10a with lithium aluminum hydride gives back the parent D-erythro alcohol exclusively, and catalytic hydrogenation saturates the olefinic double bond. These α,β-unsaturated ketones (10) in the hexose series are all levorotatory although their parent D-erythro alcohols (9) are strongly dextrorotatory; the saturated ketones derived from them are also strongly dextrorotatory. The epimeric D-threo alcohols which should also be oxidizable to 10 are however strongly levorotatory.

THE STRUCTURE OF RHYNCOPHYLLINE

1957 ◽  
Vol 35 (10) ◽  
pp. 1102-1108 ◽  
Author(s):  
J. C. Seaton ◽  
Léo Marion
Keyword(s):  
Double Bond ◽  
Hydrochloric Acid ◽  
Sodium Borohydride ◽  
Dilute Hydrochloric Acid ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Aldehyde Group ◽  
Lithium Aluminum ◽  
Total Structure ◽  
Hydrolysis Of

It is shown that hydrolysis of rhyncophylline with dilute hydrochloric acid gives rhyncophyllal (C19H24O2N2), which contains an aldehyde group but no longer contains the methoxyl, the isolated double bond, and the carbomethoxy group originally present in the alkaloid. Rhyncophyllal is reduced by sodium borohydride to the corresponding alcohol, rhyncophyllal, and this is further reduced by lithium aluminum hydride to dihydrodesoxy-rhyncophyllal (C19H28ON2), which shows the properties of an aromatic amine. Reduction of rhyncophyllal by the Wolff-Kishner reaction gives rhyncophyllane (C19H26ON2), which, when dehydrogenated over palladium–charcoal, yields 3,4-diethylpyridine. Direct dehydrogenation of rhyncophyllal produces β-collidine. On the basis of these as well as previously described results a total structure for rhyncophylline is derived.

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