480 research outputs found
Rethinking Indirect Victim Eligibility for U Non-Immigrant Visas to Better Protect Immigrant Families and Communities
Federal Anti-Sanctuary Law: A Failed Approach to Immigration and a Poor Substitute for Real Reform
UM Lands $1.2 Million Grant to Benefit Math Teachers
Center for Mathematics and Science Education kicks off Project C4 to enhance classroom effort
Rethinking Indirect Victim Eligibility for U Non-Immigrant Visas to Better Protect Immigrant Families and Communities
David Cole, Enemy Aliens: Double Standards and Constitutional Freedoms in the War on Terrorism (2003)
The chemistry of humulene
Introduction.
Plants, fungi and corals have provided a rich source of naturally occurring compounds whose occurrence, structural elucidation, and biogenesis have proved of great interest to the organic chemist. Historically, it was the high proportion of terpenes, particularly the sesquiterpenes, in essential oils of plants that first commanded attention. In 1895 Chapman isolated a sesquiterpene from oil of hops which he distinguished from caryophyllene by the preparation of a number of derivatives and suggested the name humulene. The structure of humulene, however, remained a mystery for over fifty years. Later work showed it to be monocyclic and to possess three double bonds which were not in conjugation. The position and stereochemistry of the double bonds were then deduced by degradative experiments and analysis of n.m.r. spectroscopic data, which placed them as endocyclic and all trans. The structure of humulene was confirmed as (1) by X-ray analysis of the bis-silver nitrate adduct
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