Efficient Synthesis of the Anticancer Drug Etoposide 4‘-Phosphate:  Use of Benzylic Ether-Protecting Groups on the Carbohydrate Segment1

2000 ◽  
Vol 4 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Lee J. Silverberg ◽  
John L. Dillon ◽  
Purushotham Vemishetti ◽  
Paul D. Sleezer ◽  
Robert P. Discordia ◽  
...  
Synthesis ◽  
2018 ◽  
Vol 51 (04) ◽  
pp. 971-975 ◽  
Author(s):  
Vincent Reboul ◽  
Thomas Glachet ◽  
Xavier Franck

An efficient synthesis of racemic atuveciclib was accomplished in five steps with an excellent 51% overall yield, using cheap reagents and mild reaction conditions. The key sulfoximination reaction was realized during the last step of the synthesis from the corresponding sulfide.


2021 ◽  
Author(s):  
◽  
Michael Meijlink

<p>Azasugars [e.g., 1-deoxy-aza-xylopyranose (1) Figure 1] are structural analogues of sugars [e.g., α-D-xylopyranose (2)] where the ring oxygen is substituted by a nitrogen atom. The resemblance of azasugars to their carbohydrate counterparts gives them various biological properties, such as the inhibition of glycosidase and glycosyltransferase enzymes, and as such, these compounds have been in clinical trials for the treatment of AIDS, diabetes,and cancer. Synthetic routes to azasugars have often involved the use of protecting groups, and therefore have generally reduced efficiency by requiring additional steps to apply or remove protecting groups or requiring adjustment of stereochemistry during the synthesis. This thesis presents the first example of a synthesis of four sterochemically different piperidine triols through a four-step methodology minimising the use of protecting groups starting from pentoses. The synthesis of D-xylose derived (3R,4r,5S)-piperidine triol was previously obtained in 40% yield over five steps, but was afforded in 45% overall yield over four steps using the methodology described within this thesis. Next, D-ribose derived (3R,4s,5S)-piperidine triol was obtained in 40% overall yield over four steps, which afforded a vast improvement on the previous most efficient synthetic route obtaining the azasugar in 24% yield over four steps. This four-step three-pot methodology has thus allowed for the synthesis of these piperidine triols in overall yields ranging from 4-69%, surpassing previous total syntheses in efficiency and improving overall atom economy. To further probe the applicability of the methodology, N-alkyl analogues (such as butyl-, phenylethyl-, and hydroxyethyl-analogues) of all four different piperidine triols were synthesised in comparable or greater overall yields compared to literature reports without any required adaptation to the original procedure. Included in these N-alkyl analogues are seven novel azasugars which were obtained in overall yields ranging from 6-35%.</p>


ChemInform ◽  
2010 ◽  
Vol 27 (17) ◽  
pp. no-no
Author(s):  
M. H. B. STOWELL ◽  
R. S. ROCK ◽  
D. C. REES ◽  
S. I. CHAN

Synthesis ◽  
2017 ◽  
Vol 50 (05) ◽  
pp. 1113-1122 ◽  
Author(s):  
Santosh Tilve ◽  
Sandesh Bugde ◽  
Prajesh S.Volvoikar

An efficient synthesis of naturally occurring 1,2- and 1,3-amino alcohol unit containing 2-substituted piperidine alkaloids and their analogues has been developed from l-pipecolinic acid. The protocol describes the regio- and stereoselective oxymercuration–demercuration of 2-alkenyl piperidines based on protecting groups to give piperidine alkaloids as a key step.


Pteridines ◽  
2008 ◽  
Vol 19 (1) ◽  
pp. 72-78 ◽  
Author(s):  
Tadashi Hanaya ◽  
Kiyoshi Torigoe ◽  
Kazuyuki Soranaka ◽  
Hiroshi Fujita ◽  
Wolfgang Pfleiderer ◽  
...  

AbstractN2-(N,N-Dimethylaminomethylene)-3-[2-(4-nitrophenyl)ethyl]-1',2'-di-O-(trimethylsilyl)biopterin (4) was prepared from biopterin (1a, 86% overall yield) in 5 steps. Glycosylation of 4 with 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose (5a) and its 2,3,5-tri-O-benzoyl analog (5b) respectively afforded the corresponding 2'-O-(2,3,5-tri-Oacetyl- and 2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)biopterin derivatives (6a, 42% and 6b, 60%) as major products. Removal of the protecting groups of 6b provided 2'-O-(β-D-ribofuranosyl)biopterin (1c, 87% overall yield) in 3 steps.


1995 ◽  
Vol 36 (26) ◽  
pp. 4563-4566 ◽  
Author(s):  
Steven A King ◽  
Brenda Pipik ◽  
Andrew S Thompson ◽  
Ann DeCamp ◽  
Thomas R Verhoeven

2020 ◽  
Author(s):  
Felix Schäfers ◽  
Linda Quach ◽  
J. Luca Schwarz ◽  
Mar Saladrigas ◽  
Constantin G. Daniliuc ◽  
...  

<p>A dual catalytic strategy enables the efficient synthesis of mono-protected homoallylic 1,2-diols by coupling abundant aldehydes with simple (silyl) enol ethers, thus providing direct access to this important motif without the (super)stoichiometric use of prefunctionalized metal-allyl species. A variety of silyl- and alkyl-based protecting groups is shown and functional group tolerance, chemoselectivity and scalability are highlighted. </p>


1988 ◽  
Vol 53 (11) ◽  
pp. 2778-2786 ◽  
Author(s):  
Leif Grehn ◽  
Ulf Ragnarsson

An efficient synthesis of benzyl tert-butyl iminodicarbonate (IV), starting from benzoyl isocyanate, is reported. Reaction of the isocyanate with benzyl alcohol gave benzyl N-benzoylcarbamate (II) which on exhaustive tert-butoxycarbonylation via the non-isolated triacyl amine III, after aminolysis, provided the title compound. The sodium salt V was alkylated with various halides under Gabriel conditions to give in high yields the corresponding benzyloxycarbonyl tert-butoxycarbonyl diprotected amines. Similarly, compound IV was alkylated with alcohols under Mitsunobu conditions to give some additional amines of this type, from which the protecting groups can be removed selectively under mild conditions.


1996 ◽  
Vol 37 (3) ◽  
pp. 307-310 ◽  
Author(s):  
Michael H.B. Stowell ◽  
Ronald S. Rock ◽  
D.C. Rees ◽  
Sunney I. Chan

2020 ◽  
Author(s):  
Felix Schäfers ◽  
Linda Quach ◽  
J. Luca Schwarz ◽  
Mar Saladrigas ◽  
Constantin G. Daniliuc ◽  
...  

<p>A dual catalytic strategy enables the efficient synthesis of mono-protected homoallylic 1,2-diols by coupling abundant aldehydes with simple (silyl) enol ethers, thus providing direct access to this important motif without the (super)stoichiometric use of prefunctionalized metal-allyl species. A variety of silyl- and alkyl-based protecting groups is shown and functional group tolerance, chemoselectivity and scalability are highlighted. </p>


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