%0 Journal Article
%A Woźniak, Lucyna A.
%A Wieczorek, Michał
%A Pyzowski, Jarosław
%A Majzner, Wiesław
%A Stec, Wojciech J.
%D 1998
%T Stereochemistry of the DBU/LiCl-Assisted Nucleophilic
Substitution at Phosphorus in Nucleoside-3‘-O-(Se-methyl
Methanephosphonoselenolate)s†
%U https://acs.figshare.com/articles/journal_contribution/Stereochemistry_of_the_DBU_LiCl-Assisted_Nucleophilic_Substitution_at_Phosphorus_in_Nucleoside-3_-_i_O_i_-_i_Se_i_-methyl_Methanephosphonoselenolate_s_sup_sup_/3710673
%R 10.1021/jo980225g.s001
%2 https://ndownloader.figshare.com/files/5801412
%K methyl
%K N 4
%K DBU
%K Px
%K DMT
%K configuration
%K FAST
%K assignment
%K phosphorus atom
%K Se
%K C Bz
%X The crystal and molecular structure of diastereomerically pure N4-benzoyl-2‘-deoxycytidine 3‘-O-(Se-methyl methanephosphonoselenolate (FAST-eluted) (4, R = H, B = CBz) and 5‘-O-pixylthymidine
3‘-O-(S-methyl methanephosphonothiolate (FAST-eluted) (5) have been elucidated by X-ray
crystallography. The absolute configuration at the phosphorus atom in both compounds is SP. Each
FAST-4‘ (R = DMT, B = CBz) and FAST-5 (R = Px, B = Thy) in the process of DBU/LiCl-assisted
condensation with 3‘-O-acetyl-N4-benzoylcytidine and 3‘-O-acetylthymidine gave after deprotection
(SP)-dicytidine-(3‘,5‘)-methanephosphonate and (SP)- dithymidine-(3‘,5‘)-methanephosphonate, respectively. Unambiguous assignment of the absolute configuration at the phosphorus in 4 (R = H,
B = CBz) and 5 (R = Px, B = Thy) allows for stereochemical correlation and the conclusion that
DBU/LiCl-assisted nucleophilic substitution at phosphorus occurs with net inversion of configuration,
in contrast to our earlier erroneous deduction. Moreover, the knowledge of the absolute
configuration at the phosphorus atom in both 4 (R = H, B = CBz) and 5 (R = Px, B = Thy) allows
for assignment of the absolute configuration at phosphorus in precursors of 4‘ and 5, such as 5‘-O-DMT-nucleoside 3‘-O- methanephosphonothioanilidates (6), methanephosphonoanilidates (8), and
methanephosphonoselenoanilidates (9).
%I ACS Publications