Criticism
In a 2007 paper Phil Baran notes that even though the textbooks state that the use of protective groups is unavoidable and that they are ideally easily added and removed, in practical terms in organic synthesis their use adds two synthetic steps (protection-deprotection sequence) to a chemical sequence and sometimes dramatically lowers chemical yield. Crucially, added complexity impedes the use of synthetic total synthesis in drug discovery. In contrast biomimetic synthesis does not employ protective groups. As an alternative, Baran presented a novel protective-group free synthesis of the compound hapalindole U. The previously published synthesis according to Baran, contained 20 steps with multiple protective group manipulations (two confirmed):
| Hapalindole U Baran 2007 protective-group free | Hapalindole U Muratake 1990 Ts protective groups in blue |
Read more about this topic: Protecting Groups
Famous quotes containing the word criticism:
“Unless criticism refuses to take itself quite so seriously or at least to permit its readers not to, it will inevitably continue to reflect the finicky canons of the genteel tradition and the depressing pieties of the Culture Religion of Modernism.”
—Leslie Fiedler (b. 1917)
“Like speaks to like only; labor to labor, philosophy to philosophy, criticism to criticism, poetry to poetry. Literature speaks how much still to the past, how little to the future, how much to the East, how little to the West.”
—Henry David Thoreau (1817–1862)
“It is from the womb of art that criticism was born.”
—Charles Baudelaire (1821–1867)