Preparation of Building Block

Tuckmantel, W., Kozikowski, A.P., and Romanczyk, L.J. Jr., Studies in polyphenol chemistry and bioactivity. 1. Preparation of building blocks from (+)-catechin. Procyanidin formation. Synthesis of the cancer cell growth inhibitor, 3-0-galloyl-(2R,3R)-epicatechin-4(3,8-[3,0-galloyl-(2R,3R)-epicatechin], J. Am. Chem. Soc., 121, 12073, 1999. 

In this chapter we will summarize chemical methods for the stereoselective attachment of carbohydrates to amino acids, with particular emphasis on the preparation of building blocks for use in solid-phase glycopeptide synthesis based on the 9-fluorenylmethoxycarbonyl (Fmoc) protective group strategy. 

Salvador, L., Elofsson, M., and Kihlberg, J. (1995) Preparation of building blocks for glycopeptide synthesis by glycosylation of Fmoc amino acids having unprotected carboxyl groups. Tetrahedron Lett. 51, 5643-5656. 

Scheme 4.39. Preparation of building blocks for the modular introduction of terminal amines and alcohols.

Similarly, chiral bases have found use in the preparation of building blocks for synthesis of alkaloids. A range of A-protected azabicyclic ketones was deprotonated to yield corresponding silylenol ethers (Scheme 30)68-70. The highest ee (93%) was obtained using 42 under internal quench conditions. These chiral ethers found use as key intermediates in the preparation of naturally occurring alkaloids. 

The direct allylation of radical precursors (e.g., alkyl hahdes, thioacyl derivatives) with allyltributylstannane in the presence of an initiator represents a well-established protocol for carbon-carbon bond formation [29,30]. This methodology provides a convenient means for introducing an allyl group to the anomeric carbon of carbohydrates [31]. hi their recent work on the preparation of building blocks for C-glycoside synthesis, Postema and coworkers... 

Alkynylation of zinc-copper compounds has been used for the synthesis of polyfunctional acetylenic ethers [84] and for the preparation of building blocks for pharmaceutically active compounds [85]. Whereas cross-coupling between non-activated iodoalkenes and zinc-copper reagents only proceeds at elevated temperatures and in polar solvents such as NMP or DMPU (60 12 h) [86], alkenyl... 

Christiansen-Brams, I, Meldal, M, Bock, K, Protected-mode synthesis of A-linked glycopeptides Single-step preparation of building blocks as peracetyl glycosylated Na Fmoc asparagine OPfp esters, J. Chem. Soc. Perkin Trans. 1, 1461-1471, 1993. 

The glycosylation of the OH-6 group of the myo-inositol derivative 141 with 2-azido-2-deoxy-D-glucopyranosyl trichloroacetimidates is another case of regioselective glycosylation of a 1,2-trans-O-diequatorial diol system 141 which is frequently performed for the preparation of building blocks for IPG synthesis [53]. 

Heterogeneous catalysis is one of the most powerful tools for the preparation of building blocks and fine chemicals. Reuse and recycling of heterogeneous catalysts is a milestone and a fundamental topic in the aim to introduce a green approach or an environmental friendly synthesis of scaffolds and target molecules. 

Preparation of Building Block Amino Acid Fmoc-Dp-OH (5, Fig. 3)... 

Thus (Z)-(trimethylsilyloxy)vinyllithium (1) is an excellent reagent for the preparation of building blocks such as (4), (5a), and (5b) (eq 3), which are useful for short convergent syntheses of terpenoid compounds (eqs 4 and 5). ... 

Seliger, H., Haas, B., Holupirek, M, Knable, T., Tddling, G and Philipp, M. (1980) Non-stepwise methods in the preparation of building blocks for polynucleotide synthesis. Nucl. Acids Symp. Ser. 7, 191-202... 

SCHEME 15.12 Biosynthetic pathway toward antimycins (ANTs), showing modular skeleton assembly, post-tailoring, and preparation of building blocks. KS=ketosynthase, TE=thioesterase, C=condensation, A=adenylation, T=thiolation domain, KR=ketoreductase. 

Hansen, S.G. and Skrydstmp, T. (2007) Studies directed to the synthesis of oligochitosans preparation of building blocks and their evaluation in glycosylation studies. Eur. J. Org. Chem., 3392-3401. 

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