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The critical role of stereochemistry in life, medicine, and industry mandates that stereochemistry is well represented in undergraduate lab curricula. This has primarily been achieved via experiments in the enantiomeric resolution of asymmetric acids and bases followed by polarimetric analysis, NMR analysis using chiral shift reagents, and NMR, GC, and HPLC analysis of diastereomeric derivatives of the chiral molecules. Despite the increasing prevalence of the utility of GCs and LCs fitted with chiral columns in academia and the chemical industry, they have seen limited involvement in undergraduate training. To achieve the stereochemical laboratory requirements without sacrificing existing lab techniques, we have modified two standard laboratory experiments to include chiral GC analysis as follows: (1) The extraction of carvone from spearmint leaves and caraway seeds via steam distillation or other extraction methods is a lab widely used to demonstrate stereochemistry. However, the analysis of the products from the extraction is often limited to thin-layer chromatograms that confirm the presence of carvone and shows that the enantiomers have similar polarity. By including a GC method using a β-DEX™ 225 column in this lab, students were able to compare retention times of the spearmint and caraway extracts with those in a racemic mixture, then predict whether they are R or S by comparing with an injection of a pure R-carvone sample. (2) The reduction of aldehydes and ketones is another common experiment done in most institutions. Sodium borohydride reduction of acetophenone produced a racemic mixture which was observed as two retention times on the chromatogram. Reduction using the two enantiomers of commercially available CBS catalysts provided relatively enantiopure alcohols. Students could predict which enantiomers resulted from each enantiomer of the CBS catalyst by comparing it with a commercially obtained enantiopure alcohol. They also used chromatographic data to calculate the enantiomeric excess from their reactions. The experiments also teach students other essential techniques like inert-atmosphere techniques, thin-layer chromatography, the use of multivendor software for analysis, and the effect of reaction conditions on product yield and stereochemistry

Phosphorylation is a very important biochemical process in metabolism and biochemical marking. The mechanism for the biophosphorylation of substrates and the hydrolysis/transesterification of RNA has been suggested to proceed through phosphorane intermediates. Although the phosphorane intermediate/transition state has long been a subject of many theoretical models and studies, it has neither been isolated nor characterized, with most information derived from the hydrolysis and radiolabeling of cyclic phosphotriesters. We herein present the first report of the spontaneous phosphorylation of sugars and polyols in the absence of enzymes. That is, aldehydes and ketones combine with inorganic phosphates to form activated phosphates that phosphorylate alcohols without the requirement of any enzyme or additional activating agent. This phosphorylation is particularly favored in polyhydroxycarbonyls that can form internal cyclic acetals to give rise to the corresponding acetal phosphoranes. We have further characterized these phosphoranes and demonstrated their dehydration to the corresponding phosphates by using high-resolution mass spectroscopy. The phosphorylation of adenosine and uridine to form the corresponding phosphoranes was also achieved.

Unlike the hydrocarbon analogs, this first report of enolboration–aldolization of 3,3,3-trifluoropropanoic acid provides essentially pure anti-diastereomers of α-trifluoromethyl-β-hydroxy carboxylic acids in 77–90% yields.

Unlike the reported reversible addition of ketone enolborinates to ketones, the aldolization of ketones with bisboron enediolates derived from carboxylic acids proceeds without difficulty. A variety of α,β,β-trisubstituted-β-hydroxy acids have been thus synthesized in good to excellent yields and diastereoselectivities.

DCC-mediated cyclodehydration of α-trifluoromethyl-β-hydroxy acids provides α-trifluoromethylated β-lactone intermediates, without loss of stereoselectivity. These lactones undergo facile decarboxylation providing a simple route to obtain both alkyl and aryl 1-trifluoromethyl alkenes in excellent yields and stereoselectivity.

A systematic examination of enolboration–aldolization of propanoic acid has led to an efficient synthesis of anti -β-hydroxy-α-methyl carboxylic acids in consistently high yields and diastereoselectivities by using B -bromodicyclohexylborane as the enolization reagent and triethylamine as the base.

The reaction is based on the anti-stereoselective enolboration-aldolisation of 3,3,3-trifluoropropanoic acid with aryl or alkylaldehydes.

A systematic examination of enolboration–aldolization of propanoic acid has led to an efficient synthesis of anti -β-hydroxy-α-methyl carboxylic acids in consistently high yields and diastereoselectivities by using B -bromodicyclohexylborane as the enolization reagent and triethylamine as the base.