Synthetic
Methodology

Brewster, William K; Fields, Stephen C.; Lo, William C. and Lowe, Christian T. “Electrophilic Fluorination: The Aminopyridine Dilemma”  Tetrahedron Lett. 2009, 51, 79.

Abstract:  An unusually high yielding fluorination of aminopyralid using F-TEDA (SELECTFLUOR) in warm water, followed by kinetic resoln. (via iterative esterification/sapon.) of the crude fluorination product with dry HCl in methanol produced pure ring-fluorinated pyridine in an overall yield of 31% for the two steps.

Erickson, W. R. "Early Synthetic Studies Toward The Kempane Ring Systems" presented at the 1989 Fall ACS Scientific Meeting, November 11, 1989, Midland, Michigan.

Abstract:  Utilizing a Birch reduction alkylation sequence, the initial stereocenters of the kempane terpenoid ring system were established.  Subsequent side chain homologation and cyclizations toward the A/B ring system is presented.

Balko, T.W.; Fields, S. C., Webster, J . D. "Preparation of 8’-Trifluoromethyl Abscisic Acid”, Tetrahedron Lett. 1999, 40, 6347.

Abstract:  While 8'-trifluoromethylabscisic acid (I) was known to be one of the most active and stable analogs tested in assays for ABA-like activity, a thorough evaluation of its biol. properties was limited by compd. availability.  The current synthesis, which includes the prepn. of a previously unknown key intermediate 2-methyl-2-trifluoromethyl-1,4-cyclohexanedione-mono ethylene ketal (II), has been accomplished in 14 steps and 3% yield.  The key fluorinated ketal intermediate II was prepd. in six steps and 20% yield.

Dent, W. H.; Erickson, W. R.;  Fields, S. C.; Parker, M. H.; Tromiczak, E. G.  "Preparation and Utility of 9-BBN-Protected Amino Acids for Functionalization of Amino Acid Sidechains”.  Org. Chem. Lett. 2002, 1241.

Abstract:  9-Borabicyclononane (9-BBN) derivs. of amino acids I [R = (CH2)4NH2, (CH2)3NH2, CH2C6H4OH-4, CH2OH, CH2SH, CH2CO2H, (CH2)3NHC(:NH)NH2] have been prepd.  The 9-BBN group imparts org. soly. to otherwise hydrophilic mols. and is tolerant of a wide range of reaction conditions.  The high degree of soly. of these mols. in THF is particularly noteworthy.  I is cleaved with either aq. HCl or by exchange with ethylenediamine in methanol.

Erickson, W. R.; McKennon, M. J.  "Unexpected Truce-Smiles Type Rearrangement of 2‑(2’‑Pyridyloxy) phenylacetic Esters:  Synthesis of 3‑pyridyl-2-benzofuranones".  Tetrahedron Lett.,2000, 41, 4541.

Abstract:  Enolization of (pyridyloxy)phenylacetic acid esters I (R, R1 = 6-F3C, H; 3-F3C, 5-Cl; H, H; 3-Cl, H) with either KH or NaH induced a Truce-Smiles rearrangement, producing the pyridinylbenzofuranones II.  Rearrangement of a 2-(4-nitrophenoxy)phenylacetate and a 2-(2'-pyrimidyloxy)phenylacetate produced similar results.  The benzofuranones II with a substituent at C-3 of the pyridine ring underwent enolization to the corresponding benzofuranols.