Many-Membered Carbon Rings. Iv. Synthesis of Cyclononyne and Cyclodecyne

Abstract

LToI. 7:: @-carbon of serine underwent approximately the same dilution.The methyl group of the thymine, isolated in experiment 1, had an activity of 7360 c . p m 3 and 0.0126 atom D. This would indicate a dilution of 43 for the carbon and 57 for the D.A contribution of D to the methyl groups from the ar position of serine (via a-deuterioglycine6), which would significantly change these ratios, is unlikely, since glycine is a poor source of methyl group^,^*^ and the a-hydrogen atoms of glycine' and (1) This method was conceived prior to 1946 as an alternative to the approach of Johnson, Jones and Schneider (ref. 2); see also the M.S. thesis of W. P. Schneider, University of Wisconsin, 1946. A similar approach has been suggested independently by

Strain-Promoted 1,3-Dipolar Cycloaddition of Cycloalkynes and Organic Azides

“…In the second half of the previous century, interest emerged at several laboratories around the world to explore the synthesis and properties of medium-sized cycloalkynes. Pioneers in the field, Blomquist et al, at Cornell University (USA), convincingly demonstrated in 1951 that plain cyclononyne and cyclodecyne could be accessed by oxidative decomposition of the respective cycloalka-1,2-diones, and isolated in pure form by distillation [ 7 ]. Two years later, the same group also reported the successful preparation of the eight-membered ring acetylene [ 8 ], while similar explorations on cycloalkynes were reported by Prelog and colleagues at the ETH in Zurich (Switzerland) around the same time [ 44 ].…”

Strained cyclic cumulenes

“…Waali and Allison have reported that the highly unsaturated allene 33 may be prepared by the classic carbenoid route. This compound could not be isolated; its intermediacy was inferred from a 36% yield of indene (35). 36 Similar preparation of a dibenzo derivative yielded 37.…”

Synthesis of Substituted Cyclooctenes through Cross-Coupling Reactions

“…The unique properties of strained olefins in medium-sized rings, such as cyclooctenes, have garnered significant attention. 3 The structural features 4 and planar chirality 5 6 of cyclooctenes have been extensively studied. trans -Cyclooctenes (TCOs) also display high reactivity and chemoselectivity toward organic reactions such as inverse electron-demand Diels–Alder reactions, making these olefins valuable in orthogonal bioconjugation reactions.…”