Improved Procedure for Conversion of Penicillin V Into Monocyclic β-Lactams

1987 ◽  
Vol 40 (1) ◽  
pp. 223 ◽  
Author(s):  
M Davis ◽  
WY Wu
Keyword(s):  
Manganese Dioxide ◽  
Room Temperature ◽  
Aqueous Methanol ◽  
Penicillin V

Improved procedures for the preparation of the Kamiya compound (3 R,4R)-4-(benzothiazol-2′-yldithio)-3-phenoxyacetamidoazetidin-2-0 (6) from penicillin V (1) are described. A novel feature is ozonolysis, near room temperature, in aqueous methanol in the presence of pyridine or a trace of manganese dioxide.

scholarly journals Electrochemical Corey–Winter reaction. Reduction of thiocarbonates in aqueous methanol media and application to the synthesis of a naturally occurring α-pyrone

2018 ◽  
Vol 14 ◽  
pp. 547-552 ◽  
Author(s):  
Ernesto Emmanuel López-López ◽  
José Alvano Pérez-Bautista ◽  
Fernando Sartillo-Piscil ◽  
Bernardo A Frontana-Uribe
Keyword(s):  
Room Temperature ◽  
Supporting Electrolyte ◽  
Trichoderma Viride ◽  
Chemical Yield ◽  
Vitreous Carbon ◽  
Aqueous Methanol ◽  
High Chemical ◽  
Naturally Occurring ◽  
Divided Cell ◽  
Stereo Selectivity

An electrochemical version of the Corey–Winter reaction was developed giving excellent results in aqueous methanol media (MeOH/H2O (80:20) with AcOH/AcONa buffer 0.5 M as supporting electrolyte), using a reticulated vitreous carbon as cathode in a divided cell. The electrochemical version is much more environmentally friendly than the classical reaction, where a large excess of trialkyl phosphite as reducing agent and high temperatures are required. Thus, cathodic reduction at room temperature of two cyclic thiocarbonates (−1.2 to −1.4 V vs Ag/AgCl) afforded the corresponding alkenes, trans-6-(pent-1-enyl)-α-pyrone and trans-6-(pent-1,4-dienyl)-α-pyrone, which are naturally occurring metabolites isolated from Trichoderma viride and Penicillium, in high chemical yield and with excellent stereo selectivity.

Manganese dioxide-filled hierarchical porous nanofiber membrane for indoor air cleaning at room temperature

2020 ◽  
Vol 605 ◽  
pp. 118094 ◽  
Author(s):  
Min Hu ◽  
Linghui Yin ◽  
Huixian Zhou ◽  
Lvxiong Wu ◽  
Kai Yuan ◽  
...  
Keyword(s):  
Manganese Dioxide ◽  
Indoor Air ◽  
Room Temperature ◽  
Nanofiber Membrane ◽  
Air Cleaning ◽  
Hierarchical Porous ◽  
Porous Nanofiber

scholarly journals An Efficient Synthesis and In vitro Cytostatic Activity of 5-Aminosulfonyl Uracil Derivatives

2019 ◽  
Vol 92 (2) ◽  
pp. 269-277
Author(s):  
Hamit Ismaili ◽  
Josipa Matić ◽  
Biserka Žinić ◽  
Ljubica Glavaš-Obrovac ◽  
Marijana Jukić ◽  
...  
Keyword(s):  
Antiproliferative Activity ◽  
Room Temperature ◽  
Efficient Synthesis ◽  
Aqueous Methanol ◽  
Uracil Derivatives ◽  
Product Mixture ◽  
Crude Product ◽  
I Cells ◽  
Mdck I

Efficient synthesis of 5-aminosulfonyl uracil derivatives 2-9 and results of their antiproliferative activity are provided. Sulfonylation of the amino group in 5-aminouracil 1 with selected arylsulfonyl chlorides occurs regioselectively when the reaction is carried out in pyridine at room temperature. Simple isolation of the products by recrystallization of the crude product mixture from aqueous methanol provides good to excellent yields. The prepared 5-aminosulfonyl uracil derivatives 2-9 were tested for the antiproliferative activity on a panel of seven tumor cell lines of different histological origin (HeLa, Caco-2, NCI-H358, Raji, HuT78, Jurkat, K562) and normal MDCK I cells. Derivatives 2-9 were found more efficient to lymphoma and leukemia cells compared to solid tumor and normal cells.

Effect of crystal structure of manganese dioxide on response for electrolyte of a hydrogen sensor operative at room temperature

2013 ◽  
Vol 183 ◽  
pp. 641-647 ◽  
Author(s):  
Hideki Koyanaka ◽  
Yoshikatsu Ueda ◽  
Ken Takeuchi ◽  
Alexander I. Kolesnikov
Keyword(s):  
Crystal Structure ◽  
Manganese Dioxide ◽  
Room Temperature ◽  
Hydrogen Sensor
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