Isobutyloxycarbonyl function

The tert-BOC and CBz functions have not yet found significant use in the protection of base amino functions. The only carbamate that has found extensive use is the isobutyloxycarbonyl function. This may be introduced by reaction of the nucleoside with isobutyryl chloroformate followed by deacylation of the sugar moiety ... 

The isobutyloxycarbonyl group has been used to block the 5 -hydroxyl function... 

The methoxycarbonyl [97a] and isobutyloxycarbonyl [99] groups have also been used to protect alcoholic hydroxyl functions. When thymidine was treated with an approximately stoicheiometric quantity of isobutyl chloroformate, reaction occurred predominantly at its 5 -hydroxyl function to give (48), which was isolated in 73% yield [99]. The steric requirements of ethyl and isobutyl chloroformates have not been compared. (6) Other carbonates... 

---

See also in sourсe #XX -- [ ]

---