ERIC JAN LEOPOLD


Resume

Specializing in:

ORGANIC SYNTHESIS, PEPTIDE CHEMISTRY, HPLC METHODS DEVELOPMENT, PURIFICATION


3909 O'NEILL Dr.

SAN MATEO, CALIFORNIA 94403-3637

(650) 522-8836 (home)

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POSITION OBJECTIVE: Consulting in synthetic organic chemisty or applications chemistry. I have broad range of experience.

EXPERIENCE:

1995 to Present: Eric J. Leopold Consulting, San Mateo, California, CONSULTANT

Consulted on peptide-resin cleavages using halotrialkylsilanes in the chemical process industry, organic synthesis and separation science.

1995 to 1999: RESEARCH ASSOCIATE TO WILLIAM S. JOHNSON, CHEMISTRY DEPARTMENT, STANFORD UNIVERSITY, Stanford, California

Conducted experiments to demonstrate the fluorine atom as a cation-stabilizing auxiliary in biomimetic polyene cyclization studies. Synthesized cyclization precursors. Prepared manuscripts for publication.

1994 to 1995: PENINSULA LABORATORIES, Belmont, California, SENIOR CHEMIST

Researched peptide-resin cleavage using trialkylhalosilanes. Developed and optimized purification of bioactive peptides for clinical trials. Lowered cost of peptide manufacturing through introduction of HPLC ion exchange. Evaluated high performance centrifugal partition chromatography for separations and purifications. Modernized HPLC analytical and manufacturing protocols. Trained chemists in chromatographic principles and proper use of equipment. Prepared process SOP's.

1991 to 1994: ALPHA 1 BIOMEDICALS, INC., Foster City, California, SENIOR CHEMIST

Discovered and developed new and practical methods for large scale peptide-resin cleavage using trialkylhalosilanes and at the same time, eliminated the side reactions of conventional mineral acid peptide-resin cleavage. Produced peptides on a large and small scale by solid phase synthesis under GMP. Developed method of analysis for amino acid-peptide coupling for higher purity in peptide synthesis. Developed and performed large scale sepa ration and purification of bioactive peptides for clinical trials. Improved existing ion exchange method of peptide purification. Evaluated HPLC columns for optimum separations. Prepared process SOP's. Trained process chemists in peptide synthesis and purification.

1984 to 1990: BECKMAN INSTRUMENTS, formally SMITHKLINE BECKMAN, Palo Alto, California, RESEARCH CHEMIST

Developed process for FMOC anchoring group in peptide synthesis. Synthesized fluoride ion cleavable silyl ether peptide-resin linkers. Performed electroorganic synthesis of chiral peptide intermediates. Perfected rapid large scale purification of peptide intermediates by vacuum dry column chromatography. Carried out analysis by FT-NMR, IR and UV. Evaluated PACE HPCE instrument. Demonstrated and perfected amino acid chirality analysis of amino acids and peptides by HPLC and capillary electrophoresis. Conducted methods development for capillary electrophoresis. Researched and developed capillary wall coatings for the elimination of electroosmosis in capillary electrophoresis to give better separations.

1977 to 1984: CHEMISTRY DEPARTMENT, STANFORD UNIVERSITY, Stanford, California, SENIOR RESEARCHER

In Collaboration with Dr. E. E. van Tamelen, 1980 to 1984, Discovered and perfected vacuum dry column chromatography. Synthesized and radiolabeled candidate structures for squalene biosynthesis. Carried out biogenetically patterned total synthesis of steroids. Discovered efficient stereoselective synthesis of homogeraniol. Demonstrated structure proof of 15-nor-18,19-dihydro squalene-2,3-oxide enzymatic cyclization. Planned and executed novel multistep syntheses

In Collaboration with Dr. W. S. Johnson, 1977 to 1980, Conducted 20 step synthesis of intermediates for biomimetic cyclization studies leading to dl-19-nor-4-pregnen-20-one. Investigated groups as cyclization terminators in biomimetic cyclization studies. Perfected dry column chromatography for analytical and preparative separations. Performed micro and macro synthesis.

1973 to 1977: SELF EMPLOYED, Palo Alto, California

Continued research of thesis on steroid D-ring conformations from new X-ray data while working as a wedding photographer, musician and precious metals investor.

1967 to 1972: ELI LILLY AND CO., Indianapolis, Indiana, SENIOR RESEARCH CHEMIST

Synthesized new insecticidal juvenile hormone mimics. Work led to a patent. Developed new light stable pyrethroid insecticides. Researched compounds for the chemical control of animal parasites. Prepared test compounds for field trials. Trained and supervised research associates.

TECHNIQUES and INSTRUMENTS:

Preparative and analytical separations using wet, dry column, vacuum dry column chromatography (for large scale separations), TLC, HPLC (normal, reverse phase), SEC, ion exchange, HPCE, HPCPC, and VPC. Distillation: spinning band, molecular (wiped film), Kugelrohr. Reverse osmosis and standard methods of purification. HPLC methods development. Spectrophotometer: IR, FT-IR, visible, UV, FT-NMR. Dielectric constants and dipole moments. Computer searching of Chemical Abstracts and other databases including World Wide Web. Content,Web graphics and Web publishing.

EDUCATION:

Postdoctoral Fellowship with Dr. W. S. Johnson, Stanford University, Stanford California.

Ph. D. in Organic Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania.

B.S. in Chemistry, Drexel University (cooperative education plan (work-study)), Philadelphia, Pennsylvania.

Publications: 

The Fluorine Atom as a Cation-Stabilizing Auxiliary in Biomimetic Polyene Cyclizations. Total Synthesis of dl-Dammarenediols. J. Org. Chem., 1999, 64, 9587-9595

Cleavage and Deprotection of Peptide Resins Using Chloro and Bromotrialkyl silanes., Peptide Res. 1995, 8, 298-300

Cleavage and Deprotection of Peptides from MBHA-Resin with Bromotrialkyl silane. Tetrahedron Lett., 1993, 34, 7713-7716

Cleavage and Deprotection of Peptides on MBHA-Resin with Hydrogen Bromide. Int. J. Peptide Protein Res.,1992, 40, 344-349

Separation of Chiral Amino Acids and Peptides by Capillary Electrophoresis with P/ACE 2000. Spectra 2000 [Deux Mille], 1991, 156, 27-28

Free Solution Capillary Electrophoresis and Micellar Electrokinetic Resolution of Amino Acid Enantiomers and Peptide Isomers with L-and D-Marfey's Reagents. J. Chrom., 1990, 516, 241-249

Presqualene Alcohol, Squalene, and Sterol Biosynthesis from Bifarnesol. Exp. Mycol., 1990, 14 (1), 74-77

Chiral Analysis of Amino Acids by Capillary Electrophoresis. Application Data, DS-737, Beckman Instruments, Palo Alto, California, 1989

Analysis of Chirality of Amino Acids and Peptides by High Performance Capillary Electrophoresis. HPCE., J. Cell Biol., 1988, 107 (6 Part 3) 217A

Separation of Chiral Amino Acids and Peptides by Capillary Zone Electrophoresis. 1988 Federation of American Societies For Experimental Biology 1988, 2 (6) Abstract 8559

Presqualene Alcohol from Gibberlla Fujikuroi. Phytochemistry, 1988, 27 (2), 628-629

Selective Hydroboration of a 1,3,7-Triene: Homogeraniol. Organic Syntheses, Coll. Vol. 7, p.258 (1990); Vol. 64, p.164 (1986).

Mechanism of Presequalene Pyrophosphate-Squalene Biosynthesis II. Synthesis of Bifarnesol. Tetrahedron Lett., 1985, 26, 3303-3306

Total Synthesis of d,l-Androst-4-ene-3-one-17-carboxylic Acid. J. Chem. Soc., Chem. Commun.,1984,721-723

Action of 2,3-Oxidosqualene Lanosterol Cyclase on 15'-Nor-18,19-dihydro-2,3-oxido-squalene. J. Am. Chem. Soc., 1982, 104, 6479-6480. See also Chemical & Engineering News, 1982, 60, (47) 32

Vacuum Dry Column Chromatography. J. Org. Chem., 1982, 47, 4592-4594

Insecticidal trans-4,8-Dimethyl-1,7-nonadienes. U. S. Patent 3,923,832. December 2, 1975

Cyclization of 4-(trans-3,7-Octadienyl)-3-methyl-2-cyclohexen-1-ol and 4-(trans,-trans-7-Methyl 3,7,11-dodecatrienyl)-3-methyl-2-cyclohexen-1-ol. J. Am. Chem. Soc., 1974, 96, 2540 -2549

Allylic Cation Promoted Olefinic Cyclizations. The Sterospecific Formation of a Tricyclic System and the Total Synthesis of d,l-Fichtelite. J. Am. Chem. Soc., 1968, 90, 5872 -5881

Steroid Ring D Torsional Angles and Conformations from X-ray Data. J. Am. Chem. Soc., 1966, 88, 3156-3157

Torsional Angles in Substituted Cyclopentanes. Ph. D. Thesis 1966

Phosphorous Derivatives of Fatty Acids. The Addition of Dialkyl Phosphonates to Unsaturated Acids and the Synthesis of Some 11- Dialkylphosphonoundecanoamides. J. Am. Oil Chem. Soc., 1965, 42, 134-136

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A Few Chemistry Links:

 

Chemfinder, A Useful Site For Chemists

Chemistry Department at Stanford

Rolf Claessen's Chemistry Index

Molecular Models

Organic Compound Database

Resources For Chemistry

Search Engines For Chemists

Web Elements

Other sites I made:

Cleavage of Peptide Resins with Halotrialkylsilanes

How to Photograph the Golden Gate Bridge

Eric's Photography

Dog Stories

Maggie's Page and Dog Issues

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Last modified: 5/25/2006