Toward L-Homo-DNA: Stereoselective de Novo Synthesis of β-L-erythro-Hexopyranosyl Nucleosides

A novel route to 2',3'-dideoxy-beta-L-erythro-hexopyranosyl nucleosides equipped with a 1'-(N-6-benzoyl-adenin-9-yl) or a 1'-(thymin-l-yl) moiety has been developed. Synthesis of the enantiopure sugar moiety was carried out by a de novo approach based on a domino reaction as the key step. N-Glycosidation was explored via either nucleobase-transfer mechanism (B = T) or in situ anomerization (B = A or T), affording target nucleosides with high overall stereoselectivity.