2,2 ’2”-Trichloroethoxycarbonyl

Triton X-100 octyl phenol ethoxylate Troc 2,2,2-trichloroethoxycarbonyl... 

The silyl protective groups on the baccatin core structure were removed under reaction conditions. Bac3 Pi = H, P2 = Bz, P4 = Ac, P7 = Pio = 2,2,2-trichloroethoxycarbonyl. 

Troc = 2,2,2-trichloroethoxycarbonyl Figure 9.72. Enantioselective amination of enolsilanes. 

Synthesis of l,2-frans-2-Acetamido-2-deoxyglycosyl Amino Acids Using Carbamate (2,2,2-Trichloroethoxycarbonyl or Allyloxycarbonyl) Protection of the Amine... 

SCHEME 3.11 Applications of trichloroacetimidates in glycosidic bond formation. Troc, 2,2,2-trichloroethoxycarbonyl. 

SCHEME 14.1 Synthesis of lipids I and II by VanNieuwenhze et al. Bn, benzyl CDI, l,l -carbonyldiimidazole DBU, l,8-diazabicyclo[5.4.0]undec-7-ene DIPEA, diisopropylethyl-amine EDC, l-ethyl-3-(3-dimethylaminopropyl)carbodiimide NHS, A-hydroxysuccinimide Pyr, pyridine TFA, trifluoroacetyl Troc, 2,2,2-trichloroethoxycarbonyl. 

SYNTHESIS (from 5-MeO-DMT). To a solution of 0.10 g 5-methoxy-N,N-dimethyltryptamine (see 5-MeO-DMT) in 5 mL benzene there was added 0.5 g 2,2,2-trichloroethyl chloroformate, and the resulting solution was held at reflux temperature for 2 days. After cooling there was added 5 mL Et20 and the organic phase washed with 2x20 mL 3N HC1 followed by 20 mL H2O. The solvent was then removed under vacuum. The residue (N-(2,2,2-trichloroethoxycarbonyl)-N-me-thyl-5-methoxytryptamine, 0.12 g) was dissolved in 2 mL acetic acid and treated... 

Treatment of A - -butyl-2,3,9,10-tetrahydrolysergamide 7a with elemental bromine or pyridinium bromide perbro-mide failed to yield a well-defined product. However, when the basic nitrogen at position 1 of 7a was masked with an acetyl (13) or 2,2,2-trichloroethoxycarbonyl group (14), bromination proceeded smoothly to yield the 12-bromo compounds 15 and 16, respectively. Removal of the labile protecting group14 from 16 afforded 17. 

An excerpt of a synthesis of the potent antitumour agent FR-900482 [Scheme 3.126] illustrates the use of an N, O-acetal with additional Af-protection in the form of a 2,2,2-trichloroethoxycarbonyl (TVoc) group (see section 8.3.7) in a multifunctional environment.244 245 The A 0-acetal survived the mildly acidic conditions required to deprotect the p-methoxybenzyl group that preceded the formation of the triflate 1263. Later, reductive cleavage of the Troc group and simultaneous hydrolysis of the oxazolidine ring was accomplished in a single... 

Carboxylation. Bredereck s reagent has been used in a simple synthesis of L-y-carboxyglutamic acid (S), an unusual natural amino add present in prothrombin and believed to be involved in elotting. The starting material is the lactam 1 derived from L-glutamic acid and available commercially. It is converted by reaction with this reagent into the enamide 2. Reaction with 2,2,2-trichloroethoxycarbonyl chloride transforms 2 into the trichloroethyl ester 3 in moderate yield. The synthesis of 5 is completed by reaction with benzyl alcohol and triethylamine followed by hy drogenolysis. ... 

Cleavage of fl-halourethanes. Eckert and Ugi have found that urethanes of this type can be cleaved to the amine by treatment with the anion of 1 in acetone or methanol at room temperature. The reaction involves alkylation followed by reductive fragmentation (equation I). The rate of cleavage depends on the structure of the blocking group 2,2,2-trichloroethoxycarbonyl derivatives (R = R = C1) are cleaved within 1-5 minutes. Cobalt(II) phthalocyanine (1) is recovered in almost quantitative yield in reusable form. 

The 2,2,2-trichloroethoxycarbonyl group is stable to acid, but somewhat labile to base. A superior protective group is the 2,2,2-trichloro-t-butyloxycarbonyl group, which is stable to both acid and base. The group is introduced by means of the stable chloroformate, prepared from chloretone (equation II). This protecting group is cleaved by the anion 2 in about 1 minute in approximately 90% yield. It is also... 

TcecCl also TrocCl 2,2,2-Trichloroethoxycarbonyl chloride (2,2,2-trichloroethyl chloroformate)... 

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