Ferf-Butoxy group

The only group 8 tris(ferf-butoxy)siloxide molecular precursor that has been reported thus far is the iron(III) complex Fe[OSi(O Bu)3]3 THE, synthesized via the reaction of FeCls with NaOSi(0 Bu)3 in THF (74%) [71,97] (Eq. 6). An... 

Nucleophilic and electrophilic radicals abstract different hydrogen atoms from butyrolactone 7.10 the ferf-butoxy radical selectively abstracts a hydrogen atom from the methylene group adjacent to the oxygen atom, whereas a boryl radical abstracts a hydrogen atom from the methylene group a to the carbonyl group. 

Sample Solution (a) ferf-Butoxy radical adds to the CH2 group of vinyl chloride. The free radical formed in this process has its unpaired electron on the carbon bonded to chlorine. 

As mentioned in Section 10.6.2, synthesis of 1-hydroxyethylene peptides can be initiated by adding a ferf-butoxycarbonyl N-protected a-amino aldehyde to an optically active Grignard reagent (Scheme 7)J11-13 This reaction affords a diastereomeric mixture of the C4 epimers of the hydroxy ether in good yields. In most cases the mixture is enriched in the 45-epimer and the epimers are readily separable. The yields and the ratios of the resulting 45- and 4R-epimers obtained from several examples of this reaction are summarized in Table 1. When this reaction was attempted with the aldehyde prepared from Aa,Ae-bis-tert-butoxycarbonyl-protected Lys, the desired product was not obtained. The anion of the Lys Ne-tert-butoxy-carbonylamino group probably reacts with the aldehyde to form a cyclic aminol that does not... 

Large alkoxy groups also provide steric stabilization. For example, tri-ferf-butoxysilanol, obtained by hydrolysis of sodium tri-terf-butoxy-silanolate, can be vacuum distilled without decomposition (8). 

---