of the earlier volumes, references to patents were accompanied by refer-
ences to the corresponding CAS abstract since it was often difficult to
access patents. The availability of actual images of all patents from
either the U.S. patent office (www.uspto.gov) or those from European
elsewhere (http://ep.espacenet.com) has turned the situation around.
There was always the rather pricey STN online when all else failed.
This volume, like its predecessors, is aimed at practicing medicinal and
organic chemists as well as graduate and advanced undergraduate students
in organic and medicinal chemistry. The book assumes a good working
knowledge of synthetic organic chemistry and some exposure to modern
biology.
As a final note, I would like to express my appreciation to the staff of the
library in Building 10 of the National Institutes of Health. Not only were
they friendly and courteous but they went overboard in fulfilling requests
that went well beyond their job descriptions.
PREFACE xiii