Associate Professor

Ph. D., 1975, Western Michigan University

Organic Chemistry

Voice: (207)-581-1177

Our group has been conducting research in the areas of total synthesis of natural and unnatural products with biological interest, the development of chiral allylsilylenes for asymmetric induction reactions, and novel halonium ion rearrangements. These synthetic efforts have been coupled with high resolution NMR examination of structure, kinetic behavior, and enantiomeric purity.

A compound called "mitometh", that was first synthesized in our laboratory, has shown outstanding potential for the treatment of cancer of the adrenal cortex. Its toxicity, ultrastructural effects, and biotransformations have been the focus of our studies to date. These investigations have allowed us to describe more accurately the metabolism of this >and similar drugs while providing the basis for the design and synthesis of analogs with less toxicity.

Another of our synthetic efforts has centered on the development of a regiospecific preparation of the first B-ring homoaporphine skeleton. The 2-benzazapine system was initially prepared using an enamine alkylation procedure followed by a regiospecific Beckman rearrangement. The Beckman rearrangement was found to be controlled by both steric and electronic (neighboring group participation) factors. Both reaction schemes were developed in our laboratories. Aryl-aryl ring coupling reactions were accomplished using both photochemical and traditional ring coupling reactions. The compounds prepared in this fashion are currently being studied for both CNS and anti-cancer activity.

A third project involves the separation, identification, and synthesis of jasmonic acid analogs. Work here at Maine has shown the existence of specific classes of organic compounds that contribute to the tuber forming process in potatoes. These plant hormones include the gibberellins, cytokinin, AABA, and the jasmonates. Our work now focuses on derivatives of jasmonic acid as specific tuber-inducing stimuli for potato leaves. We hope to identify the specific jasmonates which initiate this growth.

As an outgrowth of our synthetic efforts in Vitamin D3 chemistry, we have sought to design diastereofacially selective allylsilylenes as versatile platforms for allyl addition reactions with chiral aldehydes. Our preliminary studies have shown that allylsilylenes prepared from bicyclo[3.3.1] systems possess structural features that combine to make them uniquely diastereoselective. Upon reaction of the compounds with chiral a-alkoxy aldehydes in the presence of a Lewis acid, good to excellent yields of the corresponding homoallylic alcohols have been realized with diastereofacial selectivities as high as 200:1. We currently are preparing new chiral auxiliaries based on the 10-phenylpinanediol platform. The chirality of this platform, the stereogenic silicon center, and the chirality of the reacting aldehyde should provide double stereodifferentiation in the Hosami-Sakurai reaction.

With the assistance of funding from our NSF-ILI grant, the University's Bird and Bird fund, and Technology Fund of the College of Liberal Arts and Sciences , I have been working to introduce molecular mechanics calculations into the undergraduate laboratory course in organic chemistry. Take a look HERE at some of what we have been doing.