Synthesis of deoxysugars and of deoxynucleosides from diol thiocarbonates

Radical reduction of cyclic xanthates: Formation of alkenes and/or 1,3‐oxathiolanes from 1,3‐oxathiolane‐2‐thiones

“…These types of radicals produced alkenes through essentially the same reaction mechanism. However, a P-(tributylstanny1thio)carboxy alkanyl radical, presumably produced by a tin hydride reaction involving a 1,3-dioxoIane-2-thione, actually gave an alkane, as shown in Scheme 6, in which the typical deoxygenation process occurred at the secondary carbon center [13]. The difference between the reactions of 1,3-oxathiolane-2-thione and 1,3-dioxolane-2-thione would be due to an excellent ability of the [(stannylthio)thiono]oxy group but an unfavorable ability of the (stanylthio)carboxy group to undergo the @elimination step.…”

“…13 R i) Bu"$M-I, cat. AIBN Tz * s ii) hydrolysis SCHEME 6 served in the cases of alkene 3a and 1,3-oxathiolane 4a preparations.…”

Deoxy sugars. General methods for carbohydrate deoxygenation and glycosidation

“…1B). 81 Subsequently, the reaction was extended to phenyl thionocarbonates (v), 82–85 including those with electron-withdrawing substituents in the aromatic rings, 86,87 cyclic thionocarbonates (vi), 88–90 and more recently thionourethanes (vii) 91,92 (Fig. 4B).…”

Estratégias para a síntese de desoxinucluosídeos

“…Forma-se exclusivamente o produto C-5-desoxi 59. Esta seletividade é atribuída à maior estabilidade do radical secundário (em C 5 ) quando comparada a do radical primário (em C 6 ) (Esquema 17) 84,98,99 .…”