Phenoxythiocarbonyl groups

On the basis of this result, the C3 hydroxyl was replaced with phenylselenyl, phenysulfenyl, phenoxythiocarbonyl groups or bromine, and the C2 bromine was also replaced with fluorine, chlorine, or the diethylphosphite group. Schmidt s group demonstrated that, when the C3... 

Deoxyformycin (463) was prepared as a sole product from formycin (386) by protection of 03 and 05 followed by introduction and reductive removal of a 2 -0-phenoxythiocarbonyl group (85JMC1096 89MI3) (Scheme 127). 2 -Deoxyformycin B was also prepared from formycin B according to the latter route (89MI3). 

Dideoxyformycin (470) was synthesized by reductive removal of the 2 -0-phenoxythiocarbonyl group from the 3 -deoxyformycin derivative 469 [89BBR(161)910 90S411] it was found ineffective in inhibiting HIV replication [89BBR(161)910] (Scheme 128). 

A fused OZT was obtained in the course of the reduction of vicinal azido-thiocarbonates via formation of the intermediate amine, which attacks the thiocarbonyl group (Scheme 37). The condensation reaction proved faster than the deoxygenation process for the synthesis of 2 -amino-2, 3 -dideoxyuridine50 or methyl 3-amino-4,6-0-benzylidene-3-deoxy-2-0-phenoxythiocarbonyl-a-L-talopyranoside.51... 

In another similar reaction, activation of the phenoxythiocarbonyl ester on C-2 of the thioman-noside 158 by iodonium ions leads to the anomeric thioethyl group migration to the C-2 position, yielding the l,2-fraw5 -glucoside 159 (O Scheme 71) [114]. 

Similarly, thioglycosides with a phenoxythiocarbonyl ester group at C-2 (109) undergo 1,2-migration of the anomeric phenyl- or ethylthio group when they are activated (110) by NIS/cat. TfOH. 

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