- One-Pot γ-Lactonization of Homopropargyl Alcohols via Intramolecular Ketene Trapping
-
A one-pot γ-lactonization of homopropargyl alcohols via an alkyne deprotonation/boronation/oxidation sequence has been developed. Oxidation of the generated alkynyl boronate affords the corresponding ketene intermediate, which is trapped by the adjacent hydroxy group to furnish the γ-lactone. We have optimized the conditions as well as examined the substrate scope and synthetic applications of this efficient one-pot lactonization.
- Yamane, Daichi,Tanaka, Haruna,Hirata, Akihiro,Tamura, Yumiko,Takahashi, Daichi,Takahashi, Yusuke,Nagamitsu, Tohru,Ohtawa, Masaki
-
p. 2831 - 2835
(2021/05/05)
-
- Method for preparing spirolactone
-
The invention discloses a method for preparing spirolactone. The method comprises the following steps: 1, performing a reaction on a compound shown as a formula (II) and acrolein under the action of a catalyst, alkali and Lewis acid to obtain a compound shown as a formula (III); 2, performing a reaction on the compound shown as the formula (III) and chloranil to obtain a compound shown as a formula (IV); 3, performing an addition reaction on the compound shown as the formula (IV) and thioacetic acid to obtain the spirolactone. The preparation method of the spirolactone, provided by the invention, has the advantages of a short synthetic route, cheapness and easy obtainment of used reagents, simple operation, high total yield rate, and suitability for industrial production; a novel way for preparing the spirolactone is provided.
- -
-
-
- Catalyst-free conjugate addition of thioacids to activated olefins accelerated in water
-
Michael addition of thioacetic and thiobenzoic acids to activated olefins was investigated in the presence of water under catalyst-free conditions. This process, in addition to being green, has an excellent yield. With simple filtration, high-quality products were obtained on a large scale. Competitive dithiane formation and ester cleavage were not observed. Also, excellent yield was obtained using this simple process for the final step of spironolactone synthesis.
- Marjani, Katayoun,Khalesi, Maryam,Ashouri, Akram,Jalali, Aazam,Ziyaei-Halimehjani, Azim
-
experimental part
p. 451 - 458
(2011/04/16)
-
- Cyclic amino acids and derivatives thereof useful as pharmaceutical agents
-
The invention is a novel series of cyclic amino acids which are useful in the treatment of epilepsy, faintness attacks, neurodegenerative disorders, depression, anxiety, panic, pain, neuropathological disorders, gastrointestinal disorders such as irritable bowel syndrome (IBS), and inflammation, especially arthritis. A pharmaceutical composition containing a compound of the invention as well as methods of preparing the compounds and novel intermediates useful in the preparation of the final compounds are included.
- -
-
-
- Process and device for producing liquid dosage formulations of medicinal compounds on demand from tablets and capsules
-
The present invention provides a process for preparing liquid pharmaceutical formulations on demand from tablets and capsules.
- -
-
-
- 20-keto-11β-arylsteroids and their derivatives having agonist or antagonist hormonal properties
-
The invention is directed to 20-keto-11 beta -arylsteroids of formula I: wherein R1, R6, R7, R9, R12 and X are as defined by the specification. The compounds exhibit progestational and antiprogestational activities.
- -
-
-
- Spiro-dihydroisoindole compounds
-
The present invention relates to spiroisoindolines that are antagonists at the phencyclidine receptor of the N-methyl-D-aspartate receptor complex and which are useful when such antagonism is desired such as in the treatment of neurological disorders. The invention further provides processes for preparing the spiroisoindolines, intermediates useful for their synthesis, pharmaceutical compositions containing them, and methods for their use.
- -
-
-
- 4-Aryl-1-oxa-8-azaspiro[4,5]dec-3-en-2-ones
-
This disclosure describes 8-substituted-4-phenyl-1-oxa-8-azaspiro[4,5]dec-3-en-2-ones and 8-substituted-4-phenyl-1-oxa-8-azaspiro[4,5]decan-2-ones useful as analgesic or neuroleptic agents.
- -
-
-
- Method for preparing 7α-acylthio-4-en-3-oxosteroids
-
A 7α-acylthio-4-en-3-oxosteroid such as 7α-acetylthio-17-hydroxy-3-oxo-17α-pregn-4-ene-21-carboxylic acid γ-lactone (spironolactone) which is an antialdosteronic diuretic effective in therapy is prepared by contacting a steroidal material which contains a 7β-acylthio-4-en-3-oxosteroid with a thiocarboxylic acid.
- -
-
-
- Spironolactone process
-
Spironolactone (VIII) is produced from ethisterone (I) by formation of the lactone (IV), a halo lactone (VI) and a Δ4,6-lactone (VII).
- -
-
-
- Process for the manufacture of steroid carboxylic acid lactones
-
An advantageous method for the manufacture of steroidal lactones of the spironolactone and canrenone type involves the following reaction sequence: bromination of a 3β ,17-dihydroxy-17α -pregn-5-en-21-carboxaldehyde in basic or neutral medium, oxidation of the 5,6-dibromo compound with hexavalent chromium compounds under basic or neutral conditions, dehydrobromination with inorganic basic agents, such as lithium halides in the presence of lithium carbonate, or with organic bases, such as pyridine, oxidation of the steroid-4,6-diene compound so obtained having in the 17-position the same substituents as the starting material mentioned, with compounds of hexavalent chromium in acid solution, optionally after pretreatment with an acid or, in particular, with a thiocarboxylic acid (to introduce the 7α-acylthio group, e.g. if spironolactone is to be manufactured). The new process gives better yields than those hitherto described.
- -
-
-
