TMSE, trimethylsilyl

TMSE, trimethylsilyl ethers CDMSE, chlorodimethylsilyl ethers BDMSE, bromodimethylsilyl ethers. 

Trimethylsilyl)ethyl (TMSE) Ester RC02CH2CH2Si(CH3)3 Formation... 

SCHEME 14.3 Synthesis of mycobacterial lipid II. TMSE, 2-(trimethylsilyl)ethyl. 

The total synthesis published by Schwartz and co-workers followed essentially the same approach, except they used fluoride-sensitive protective groups (such as TMSE (trimethylsilylethyl) and TEOC (trimethylsilyl-thoxycarbonyl) for pentapeptide side chains) to avoid the use of a strong base such as sodium hydroxide during the final deprotection step (22). 

In Fmoc chemistry, the tBu group is commonly used for the protection of Tyr. The TBDMS group has also been suggested for Fmoc SPPS, but, unlike the TBDMS ethers of serine and threonine, the TBDMS ether of tyrosine is less acid labile than the tBu ether [56]. However, selective deprotection can be accomplished by treatment with tetrabutylammonium fluoride (TBAF) [56]. The trimethylsilyl (TMSE) and dimethylphenylsilyl (DMPSE) groups have been shown to be compatible with Bpoc-based synthesis, but their use in Fmoc SPPS has not been reported [116]. 

Tmse ester, 2-(trimethylsilyl)ethyl ester, a carboxy protecting group, cleaved by fluoride ions. 

When MLH had overcome the mentioned difficulties and some smaller ones, he synthesized the western building block 30 via p-ketothioester 34 as summarized in Scheme 8. The route toward diester 33 of L-A-methylglutamic acid, then not a known compound, started from commercially available Cbz-protected L-glutamic acid (73). Esterification with excess 2-(trimethylsilyl) ethan-l-ol ( TMSE-OH ), DCC, and DMAP furnished the diester 74 in 82% yield." It was methylated with Mel/Ag20 (—>93% 75 of 97-98% ee) adhering to a general procedure" and conscious of a specific application to a diester of... 

Marll993 Marlowe, C.K., Peptide Cyclization on TEA Labile Resin Using the Trimethylsilyl (TMSE) Ester as an Orthogonal Protecting Group, Bioorg. Med. Chem. Lett., 3 (1993) 437- 0. 

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