Introduction of a substituent at the 5″-position of N-Boc neomycin B under Mitsunobu reaction conditions

2005 ◽  
Vol 3 (11) ◽  
pp. 2064 ◽  
Author(s):  
Angelica Hernandez Linares ◽  
Dominique Fourmy ◽  
Jean-Louis Fourrey ◽  
Ali Loukaci
2006 ◽  
Vol 36 (4) ◽  
pp. 487-493 ◽  
Author(s):  
Angelica Hernandez Linares ◽  
Dominique Fourmy ◽  
Jean‐Louis Fourrey ◽  
Ali Loukaci

ChemInform ◽  
2011 ◽  
Vol 42 (38) ◽  
pp. no-no
Author(s):  
Ramu Sridhar Perali ◽  
Suresh Mandava ◽  
Venkata Rao Chunduri

ChemInform ◽  
2005 ◽  
Vol 36 (27) ◽  
Author(s):  
Raul A. Cadenas ◽  
Maria E. Gelpi ◽  
Jorge Mosettig

1990 ◽  
Vol 31 (48) ◽  
pp. 6973-6976 ◽  
Author(s):  
Joginder S Bajwa ◽  
Robert C Anderson

1988 ◽  
Vol 29 (37) ◽  
pp. 4661-4664 ◽  
Author(s):  
Teodozyj Kolasa ◽  
Marvin J. Miller

2021 ◽  
Author(s):  
In-Soo Myeong ◽  
Nadide Hazal Avci ◽  
Mohammad Movassaghi

We report the first total synthesis of (–)-kopsifoline A and (+)-kopsifoline E. Our synthetic strategy features a biogenetically inspired regioselective C17-functionalization of a versatile intermediate containing the pentacyclic core of aspidosperma alkaloids. While this advance intermediate provides (–)-kopsifoline D via C3–C21 bond formation, regioselective C17-boronation of its indoline substructure prior to introduction of the F-ring enables access to (–)-kopsifoline A and (+)-kopsifoline E. The vinylogous urethane substructure of the key intermediate was critical in C17-boronation over a competing C7-boronation in related indole derived substrates. After oxidation of the C17–B bond to introduce the C17-ether, the C3–C21 bond of the targets is secured under the Mitsunobu reaction conditions with the vinylogous urethane as the nucleophilic component.


2000 ◽  
Vol 65 (11) ◽  
pp. 1698-1712 ◽  
Author(s):  
Zlatko Janeba ◽  
Antonín Holý ◽  
Milena Masojídková

Reaction of 8-bromoadenine derivatives 1 with thiourea in ethanol or butanol was used for the synthesis of the corresponding N9-substituted 6-amino-7H-purine-8(9H)-thiones 2. 8-(Methylsulfanyl)adenine derivatives 3 were prepared by reaction of thiones 2 with iodomethane in 1 M sodium methoxide or in aqueous 1.5 M potassium hydroxide. Alkylation of 6-amino-7H-purine-8(9H)-thione (2a) proceeds preferentially on the sulfur atom. Under similar conditions, alkylation of 8-(methylsulfanyl)adenine (3a) with diverse alkylation agents afforded N9-substituted adenine derivatives 3 and 6, and N3-substituted adenine derivatives 5 and 7. 8,3'-S-Anhydro derivatives 9 were prepared in good yields by cyclization of 6-amino-7H-purine-8(9H)-thiones 2d and 2f under the Mitsunobu reaction conditions.


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