3970-20-5Relevant articles and documents
Total syntheses of (?)-emestrin H and (?)-asteroxepin
Sakata, Juri,Tokuyama, Hidetoshi,Ueda, Yusuke,Umeki, Kanato
, (2020/11/02)
First total syntheses of (?)-emestrin H and (?)-asteroxepin are described. To find the appropriate protecting group on the amide nitrogen of the diketopiperazine core, we conducted model studies using a simple diketopiperazine derivative. As a result, allyloxymethyl (Allom) group was the most suitable protecting group, which tolerated Nicolaou's sulfenylation conditions, and was easily cleavable under the mild conditions using Pd(PPh3)4 and N,N-dimethylbarbituric acid leaving methylthioethers intact. The general utility of Allom group for protection of amides was studied using simple substrates. Finally, the effectiveness of Allom group was proved by the accomplishment of the first total synthesis of (?)-emestrin H. Allom group was robust enough during installation of two methylthioethers to the diketopiperazine core and easily removed at the final step. The first total synthesis of (?)-asteroxepin was also completed by acylation of (?)-emestrin H.
Alternative synthesis of 9-{3-[(diisopropoxyphosphoryl)-methoxy]-2- hydroxypropyl}adenine and its free phosphonates substituted at the c-8 position of purine base
Janeba, Zlatko,Masojidkova, Milena,Holy, Antonin
experimental part, p. 371 - 381 (2010/07/09)
For its high therapeutic effect, (S)-9-[3-hydroxy-2-(phosphonomethoxy) propyl]adenine (HPMPA) is an important member of a class of acyclic nucleoside phosphonates (ANPs). Although its constitutional isomer, 9-[2-hydroxy-3- (phosphonomethoxy)propyl]adenine (iso-HPMPA), exhibits no antiviral activity, our general interest in C-8 substituted adenine ANPs led us to prepare certain iso-HPMPA derivatives modified at the C-8 position of adenine. Novel alkylating agent, diisopropyl {[2-(tetrahydro-2-pyranyl)oxy-3-tosyloxypropoxy]-methyl} phosphonate (9), was prepared by procedure starting from allyl alcohol (4). 9-{3-[(Diisopropoxyphosphoryl)methoxy]-2-hydroxypropyl}adenine (12) was prepared by alkylation of adenine with the alkylating agent 9 followed by acid hydrolysis, although elimination by-product 9-{3-[(diisopropoxyphosphoryl) methoxy]prop-1-enyl}adenine (11) predominated in the reaction mixture. Bromination of the compound 12 gave 8-bromoadenine derivative 13 quantitatively. Nucleophilic substitutions of the bromine atom of compound 13 with N-and O-nucleophiles, followed by phosphonate deprotection, afforded the free phoshonic acids 15-18.
SYNTHESIS OF A NEW POTENTIAL ANTIVIRAL AGENT - 9-ALLYLOXYMETHYLGUANINE
Ozerov, A. A.,Brel', A. K.
, p. 945 - 948 (2007/10/02)
A convenient method has been developed for the synthesis of 9-allyloxymethylguanine. The direct alkylation of the trimethylsilyl derivative of guanine allyloxymethyl chloride gives a 64 percent yield of 9- and 7-allyloxymethylguanine (3:1). A mixture of 9- and 7-allyloxymethyl-N-acetylguanine (7:4) can be obtained in 56 percent yield by the condensation of diacetylguanine with allyloxymethyl acetate in dimethyl sulfoxide in the presences of p-toluenesulfonic acid.