STRATEGIES AND TACTICS IN ORGANIC SYNTHESIS, VOL. 7
© 2007 Elsevier Ltd. All rights reserved.
Chapter XX
Seduced by a Siren’s Call:
Expanding Applications for
Aromatic Compounds and the
Synthesis of (+)-Rishirilide B
Thomas Pettus and Todd Wenderski
Department of Chemistry and Biochemistry
University of California at Santa Barbara
Santa Barbara, California 93106-9510
I. A burgeoning interest in aromatic compounds .........................................................1
II. Why choose a particular phenol skeleton for oxidation? .......................................5
III. Developing easy access to various resorcinol systems ............................................7
IV. Total synthesis of (±)-epoxysorbicillinol ................................................................ 11
V. Plans for chiral auxiliaries disintergrate................................................................ 12
VI. Stereochemistry describes an unexpected transition state ................................. 12
VII. Beating the clock, tuning the reaction and improving yields ............................. 13
VIII. Controlling β -dione tautomerization and protection .......................................... 15
IX. A lactic acid derived protecting-directing group ................................................. 16
X. New methods for cleavage of the directing-protecting group ............................. 19
XI. The total synthesis of (+)-rishirilide B ................................................................... 20
XII. New horizons for this method and oxidative dearomatization .......................... 22
XIII. Acknowledgment of mentors, colleagues and other supporters ........................ 24
XIV. References .................................................................................................................. 24
I. A burgeoning interest in aromatic compounds
It’s often tough to tell when a story truly begins. I’ll start at
Virginia Tech, where I was working in the laboratories of
Professor Tomás Hudlicky, (T’Hud). My organic college
professor, Dr. Maurice Maxwell (Max), was visiting VPI for a
summer research program and had brought me along. I was
assigned to the bench of Gustavo Seoane, who served as my
immediate mentor and handler for the summer of 1988. Gustavo’s
mission, which no doubt doubled his work-load, was to prevent me
from hurting myself, others, and taking out a wall while carrying
out an experiment. T’Hud had recently recognized the importance
of a Gibson paper reporting the formation of (+)-cis-2,3-
dihydroxy-1-methyl-cyclohexadiene from toluene by a mutant
strain (39D) of the soil microbe Pseudomonas putida, and he and
his group were just beginning to finish enantioselective syntheses
of terpenes and prostanoids from arene diols (Scheme 1).
1
T’Hud