Assignment of the chemical shift values of N-trityl -homoserine lactone

This paper reports the correct assignment of all chemical shift values of N-trityl -homoserine lactone based on the 1H-nmr spectra of N-trityl-2S, 3R-[3-2H]- and 2S, 3S-[2,3-2H2]homoserine lactone.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27617/1/0000661.pd

Alternate substrates and inhibitors of 1-aminocyclopropane-1-carboxylic acid synthase

Structural analogs of (-)-S-adenosyl--methionine (SAM), in which the heterocyclic base was modified, were used to initiate studies to elucidate the active site conformation of the enzyme 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, which was partially purified from Lycopersicon esculentum (tomato). These potential substrate analogs were screened for activity both as substrates and/or as inhibitors of ACC synthase. In general, ACC synthase was found to have a rather rigid specificity for the structural features of the natural substrate (SAM) in that only the purine base adenosine and adenosine analogs in which the N6 nitrogen was modified were substrates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26684/1/0000231.pd

Synthesis of deuterium‐labeled 1‐aminocyclopropane‐1‐carboxylic acid

The syntheses of D,L‐1‐amino[2,2‐ 2 H 2 ]cyclopropane‐1‐carboxylic acid; 1‐amino [c‐2, c ‐3‐ 2 H 2 ] and 1‐amino[ t ‐2, t ‐3‐ 2 H 2 ]cyclopropane‐1‐carboxylic acid ( cis ‐[ 2 H 2 ]ACC); 1‐amino[2 S ,3 S ‐ 2 H 2 ] and 1‐amino[2 R ,3 R ‐ 2 H 2 ]cyclopropane‐1‐carboxylic acid ( trans ‐[ 2 H 2 ]ACC); and 1‐amino[2,2,3,3‐ 2 H 4 ]cyclopropane‐1‐carboxylic acid are described. The [2,2‐ 2 H 2 ]and [2,2,3,3‐ 2 H 4 ]ACC compounds were prepared from the appropriately deuterated 2‐bromoethanol 4‐methylbenzenesulfonates by reaction with ethyl isocyanoacetate and two moles of sodium hydride. The trans ‐[ 2 H 2 ]ACC and cis [ 2 H 2 ]ACC were prepared from meso and d, l ‐[1,2‐ 2 H 2 ]‐1,2‐dibromoethane respectively, by reaction with ethyl isocyanoacetate and two moles of sodium hydride. These compounds are required for use in the study of the biosynthesis of ethylene by various plants and for use in 1 H and 13 C‐NMR studies of 1‐aminocyclopropane‐1‐carboxylic acid derivatives.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90329/1/2580210907_ftp.pd

Preparation of 1-deuterioaldehydes via tub use of diisobutylaluminum deuteride (DIBAL-D)

Deuterioaldehydes, essential precursors In the preparation of chiral primary deuterioalcohols, have been prepared in yields ranging from 55-75% via reduction of methyl and ethyl esters at -78[deg]C with diisobutylaluminun deuterlde (DIBAL-D). The stoichiometry of the DIBAL-D reduction and the time of the reduction were varied depending upon the structure of the reactant. Aliphatic esters were reduced in 6-10 min. at -78[deg]C while aromatic esters were reacted for 1 hr. at -78[deg]C. From 1.0 to 1.S equivalents of DIBAL-D were used to reduce simple monofunctional esters while multifunctional esters required 2.0 to 2.5 equivalents of DIBAL-D.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25033/1/0000460.pd

A practical large scale chemical synthesis of chiral glycines

(R)- and (S)-[2-2H]glycine of high chiral purity were synthesized in large quantities in [approximate] 40% overall yield from readily available starting materials via a totally chemical procedure. Reduction of either [1-2H]-furfural or [1-2H]-4-methoxybenzaldehyde with either (+) or (-)-B-isopinocampheyl-9-borabicyclo[3.3.1]nonane gave chiral arylmethyl alcohols which were converted into their respective phthaloyl amino derivatives of the opposite configuration at the methylene carbon via the Mitsunobu reaction. The aromatic groups were oxidatively unmasked to give their corresponding glycine derivatives by either ozone or ruthenium tetraoxide oxidation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27619/1/0000663.pd