SummaryThe synthetic protocol for the reduction of alcohols to hydrocarbons by using hydriodic acid, first described by Kiliani more than 140 years ago, was improved to be more applicable to organic synthesis. Instead of a strongly acidic, aqueous solution, a biphasic toluene–water reaction medium was used, which allowed the conversion of primary, secondary and tertiary benzylic alcohols, in good yields and short reaction times, into the corresponding hydrocarbons. Red phosphorous was used as the stoichiometric reducing agent. Keto, ester, amide or ether groups are tolerated, and catalytic amounts of hydriodic acid (0.2 equiv) in the presence of 0.6 equiv phosphorous are sufficient to achieve conversion.

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We report the synthesis of pyrene-and carboxyfluorescein labeled C a -tetrasubstituted amino acids (TAAs). The fluorescent dye can be coupled to the TAA before or after its incorporation into a peptide sequence using a Suzuki-type CÀC bond formation.Introduction. -The biological activity of peptides and proteins is based on their conformation, which is related to the secondary structures of the amino acid sequence [1 -3]. In this context, the major drawback of small natural peptides is the conformational flexibility as well as the biological and chemical instability, which may hamper the investigation of biological processes or to perform structural studies. Therefore, the rational design and synthesis of peptides and peptidomimetics [4] [5] with defined structural properties [6] [7] attracted interest of chemists and biologists in the recent past. To stabilize or mimic the conformation of peptides, many different approaches were followed [8]. One very successful strategy is the disubstitution in aposition of amino acids [9], resulting in a conformational constrain and enabling this class of C