Reactions of ketones with sodium hydride or potassium hydride in the presence of trimethylsilyl chloride. Preparation of trimethylsilyl enol ethers

1978 ◽  
Vol 43 (20) ◽  
pp. 3861-3865 ◽  
Author(s):  
Paul F. Hudrlik ◽  
James M. Takacs
Keyword(s):  
Sodium Hydride ◽  
Enol Ethers ◽  
Potassium Hydride

Preparation of -butyldimethylsilyl (tbdms) enol ethers using potassium hydride in the presence of tbdms chloride

1984 ◽  
Vol 25 (44) ◽  
pp. 5099-5102 ◽  
Author(s):  
John Orban ◽  
John V. Turner ◽  
Bruce Twitchin
Keyword(s):  
Enol Ethers ◽  
Potassium Hydride

Two new diphenyl ethers and a new depside from the lichen Micarea prasina Fr

1984 ◽  
Vol 37 (11) ◽  
pp. 2349 ◽  
Author(s):  
JA Elix ◽  
AJ Jones ◽  
LCBJ Lajide ◽  
PW James
Keyword(s):  
Total Synthesis ◽  
Methyl Esters ◽  
Sodium Hydride ◽  
Hydroxybenzoic Acid ◽  
Type Synthesis ◽  
Enol Ethers ◽  
Diphenyl Ethers ◽  
Key Steps ◽  
Methoxybenzoic Acid

Two new diphenyl ethers, 4-(2-carboxy-3-heptyl-5-methoxyphenoxy)-2-heptyl-6-hydroxybenzoic acid (micareic acid) (13), 4-(2-carboxy-3-heptyl-5-methoxyphenoxy)-2-heptyl-6-hydroxy-3-methoxybenzoic acid (methoxymicareic acid) (27) and a new depside, 4-(2-heptyl-6-hydroxy-4-methoxybenzoyloxy)- 2-heptyl-6-hydroxybenzoic acid (prasinic acid) (34) have been detected in chemical races of the lichen Micarea prasina Fr. and isolated and characterized as the corresponding methyl esters. The structure of the latter compounds has been confirmed by total synthesis. The key steps in the synthesis of the diphenyl ethers (14), (26) involved Ullmann-like condensation between the 3-chloro 2-enone (17) and the phenols (11), (31), and subsequent aromatization of the enol ethers (23) and (32). A biomimetic-type synthesis of methyl micareate (48) has also been achieved by treatment of the depside (33) with sodium hydride in dimethylformamide.

Tetrahydropyranyl protecting group. II. 3-Bromo-2-(tetrahydropyran-2-yloxy)propene, a masked acetonyl bromide

1970 ◽  
Vol 48 (6) ◽  
pp. 975-982 ◽  
Author(s):  
D. E. Horning ◽  
G. Kavadias ◽  
J. M. Muchowski
Keyword(s):  
Hydrogen Bromide ◽  
Sodium Hydride ◽  
Dimethyl Formamide ◽  
Protecting Group ◽  
Enol Ethers ◽  
In Situ Formation ◽  
Group Ii

It is shown that the sodium hydride (in dimethyl formamide) induced elimination of hydrogen bromide from 1,3-dibromo-2-(tetrahydropyran-2-yloxy)propane (3) can be considered to result in the in situ formation of 3-bromo-2-(tetrahydropyran-2-yloxy)propene (4). When generated in this manner, 4 was shown to function as a masked acetonyl bromide of considerable utility. Under similar conditions, 1,3-dibromo-2-methoxypropane was assumed to produce 3-bromo-2-methoxypropene, which also was shown to be a useful masked acetonyl bromide.The pyrolytic elimination of methanol from bromoacetone dimethyl ketal was shown to produce a 1:1 mixture of the two possible isomeric enol ethers, rather than pure 3-bromo-2-methoxypropene as stated in the literature (2).

Sign in / Sign up

Export Citation Format

Share Document