My professional activities
encompass both traditional "bench" research and scholarly
efforts in the area of chemical education. As detailed below,
my bench research program is focused on carbohydrate chemistry.
My efforts in chemical education scholarship focus primarily on
the development of pedagogical materials to promote active learning
in the classroom and the laboratory.
The focus of my bench research program is synthetic carbohydrate chemistry, specifically carbocyclization reactions of carbohydrates and the use of the products of these reactions in the synthesis of biologically active compounds and in stereochemical control of organic reactions. My current interest involves the use of the Ferrier carbocyclization reaction of 5,6-unsaturated carbohydrate derivatives. This reaction involves a mecury salt mediated intramolecular aldol condensation to form highly substituted, enantiomerically pure cyclohexanones as shown below.
We are currently using the Ferrier carbocyclization methodology and the resulting products in the following two projects.
Several carbohydrate based antibiotics including kanamycin (shown
below) and gentamicin contain a 2-deoxystreptamine residue as
a central component. Total syntheses of these compounds utilize
a protected 2-deoxystreptamine along the route to the desired
product. This has long been a problem in such synthetic efforts
due to the fact that 2-deoxystreptamine is a meso compound. This
fact makes preferential glycosylation of the hydroxyl groups of
2-deoxystreptamine, a critical step in the total synthesis, impossible.
Starting from D-glucose, a chiral, naturally occurring compound,
we seek to synthesize a differentially protected, and therefore,
chiral 2-deoxystreptamine.
Our overall synthetic goal is summarized in the following scheme.
Note that the mirror plane present in unprotected 2-deoxystreptamine
is removed simply by differential protection of the #'s 4 and
6 hydroxyls.
In an attempt to control the orientation of attack the diene on
the dienophile in a Diels-Alder reaction, and thus limit the number
of potential products, we seek to synthesize chiral cyclohexenones
as potential dienophiles. The syntheses of the dienophiles
will begin with D-glucose, D-mannose,
D-galactose, and/or D-allose.
The natural chirality of these
compounds will be translated, via the Ferrier carbocyclization
reaction, into the potential dienophiles. (For example, the dienophile
dervied from D-glucose would have
all pseudo-equatorial substituents.) The utilization of each of
the other three sugars as a starting material in dienophile synthesis
will allow for the installation of a pseudo-axial substituent
at either of the three hydroxylated positions on the cyclohexenone
ring as shown below.
The reactions of the latter three dienophiles with suitable dienes will be studied and compared to the reaction of the D-glucose derived dienophile with the same dienes to discern the effect, if any, of the pseudo-axial substituents.
| Ceba Humphrey | Chemistry Major |
| Heather Eidson | Chemistry Major |
| Liz Robertroy | Chemistry Major |
| Brandon Burnsed | Biology Major |
| Brandon Smith | Chemistry Major |
| Peter Orizondo | MS, Wichita State; Great Lakes Chemical |
| Dr. Louise Bodack | Ph.D., Syracuse University; Framingham State University |
| Matt Miller | Environmental Lab Tech |
| Debbie McNeal | High School Science Teacher |
| Carisa Hodge | Psychology Graduate School |
| Susie Culpepper | Brown and Williamson, Co. |
| Kathy Gunn | High School Chemistry Teacher |
| Tonya Tolleson | |
| Fernando Carriedo | Director of Analysis, Brown & Williamson, Co. |
| Sandi Pope | Physician's Assistant, Savannah, GA |
| Rod Martin | Flight School |
| Dr. Jill Buckthal | MD, Medical College of GA, Dermatology |
| Dr. Joe Millican | MD, Medical College of GA, Surgery |
| Dr. Corbin Mullis | MD, Medical College of GA, ENT |
| Dr. Jeff Winge | MD, Mercer University, Emergency Medicine |
| Jan Williams | Ph.D. Program Medical College of Georgia |
| Katie Farmer | MS, Virginia Tech |
| Brian Stansfield | MD Program Medical College of GA |
| Dontarie Stallings | Ph.D. Program at University of Alabama |
| Jelana Hamilton | Graduate Study at University of Alabama |
| Cliff Lovett |