TBDMS, /-butyldimethylsilyl

The triethylsilyl ether is approximately 10-100 times more stable than the TMS ether and thus shows a greater stability to many reagents. Although TMS ethers can be cleaved in the presence of TES ethers, steric factors will play an important role in determining selectivity. The TES ether can be cleaved in the presence of a /-butyldimethylsilyl ether using 2% HE in acetonitrile. In general, methods used to cleave the TBDMS ether are effective for cleavage of the TES ether. 

AC2O, FeCl3, It, <30 min, 60-93% yield. These conditions will selectively protect an aldehyde in the presence of a ketone. This combination also converts r-butyldimethylsilyl (TBDMS) ethers to acetates. 

Butyldimethylsilyl Ester (TBDMS Group) RCOOSi(CH3)2C(CH3)3 (Chart 6)... 

Recently, multidimensional GC has been employed in enantioselective analysis by placing a chiral stationary phase such as a cyclodextrin in the second column. Typically, switching valves are used to heart-cut the appropriate portion of the separation from a non-chiral column into a chiral column. Heil et al. used a dual column system consisting of a non-chiral pre-column (30 m X 0.25 mm X 0.38 p.m, PS-268) and a chiral (30 m X 0.32 mm X 0.64 p.m, heptakis(2,3-di-(9-methyl-6-(9-tert-butyldimethylsilyl)-(3-cyclodextrin) (TBDM-CD) analytical column to separate derivatized urinary organic acids that are indicative of metabolic diseases such as short bowel syndrome, phenylketonuria, tyrosinaemia, and others. They used a FID following the pre-column and an ion trap mass-selective detector following the... 

The following abbreviations are commonly used for substituent groups in structural formulae Ac (acetyl), Bn or PhCH2 (benzyl), Bz or PhCO (benzoyl), Et (ethyl), Me (methyl), Me3Si (not TMS) (trimethylsilyl), Bu Me2Si (not TBDMS) (rerf-butyldimethylsilyl), Ph (phenyl), Tf (triflyl = trifluoromethanesulfonyl), Ts (tosyl = toluene-p-sulfonyl), Tr (trityl). 

The synthesis of 5-phosphono-l,2,4-triazolin-3-one 137 began with the low-temperature metalation and phosphorylation (77) of the f-butyldimethylsilyl (TBDMS)-protectedlV-benzyl-tiiazolinone 134. The phosphonate diester 135 was obtained ter the silyl protecting group... 

PyBroP bromo(tripyrrolidino)phosphonium hexafluorophosphate TBS TBDMS, ferf-butyldimethylsilyl... 

The tert-butyldimethylsilyl (TBDMS) protection of 50 gave a silyl ether... 

Table 7.1 reports the ions commonly used in SIM acquisition for the quantification of trimethylsilyl (TMS) and f-butyldimethylsilyl (TBDMS) derivatives. 

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