Faulknerynes A−C from a Bahamian Sponge Diplastrella sp.: Stereoassignment by Critical Application of Two Exciton Coupled CD Methods
摘要:
Long-chain polyacetylene alcohols, faulknerynes A-C, along with known compounds diplynes A, C and E, were isolated from two specimens of the encrusting sponge, Diplastrella sp., collected from the surface of coral in the Bahamas. Two CD methods were critically evaluated for their suitability to terminal propargylic glycols and applied to assignment of configurations of faulkneryne A and diplyne C.
Chlorocyclopropane Macrolides from the Marine Sponge <i>Phorbas</i> sp. Assignment of the Configurations of Phorbasides A and B by Quantitative CD
作者:Colin K. Skepper、John B. MacMillan、Guang-Xiong Zhou、Makoto N. Masuno、Tadeusz F. Molinski
DOI:10.1021/ja0703978
日期:2007.4.1
chlorocyclopropane macrolides, phorbasides A and B, have been characterized from the spongePhorbassp. that previously yielded phorboxazoles A and B. We describe the assignment of the absoluteconfiguration of the trans-chlorocyclopropane ring that exploits a CD Cotton effect arising from hyperconjugation to the ene-yne chromophore. Phorbasides and callipeltoside A share the same macrolideconfigurations but, unexpectedly
两种新的氯环丙烷大环内酯,佛巴苷 A 和 B,已从海绵 Phorbas sp. 中得到表征。先前产生佛盒唑 A 和 B。我们描述了反式氯环丙烷环的绝对构型的分配,该环利用了由于与烯-炔生色团的超共轭而产生的 CD 棉花效应。Phorbasides 和 callipeltoside A 具有相同的大环内酯构型,但出人意料的是,环丙烷构型相反。
Catalytic Asymmetric Addition of Terminal Alkynes to Aldehydes Mediated by (1R,2R)-2-(Dimethylamino)- 1,2-diphenylethanol
Catalyticasymmetric alkynylation of aldehydes with terminalalkynes was catalyzed by zinc triflate and (1R,2R)-2-(dimethylamino)-1,2-diphenylethanol in toluene to give the corresponding alcohols with high enantiomeric excess up to 98% in good yields.
Faulknerynes A−C from a Bahamian Sponge <i>Diplastrella</i> sp.: Stereoassignment by Critical Application of Two Exciton Coupled CD Methods
作者:Jaeyoung Ko、Brandon I. Morinaka、Tadeusz F. Molinski
DOI:10.1021/jo102188q
日期:2011.2.4
Long-chain polyacetylene alcohols, faulknerynes A-C, along with known compounds diplynes A, C and E, were isolated from two specimens of the encrusting sponge, Diplastrella sp., collected from the surface of coral in the Bahamas. Two CD methods were critically evaluated for their suitability to terminal propargylic glycols and applied to assignment of configurations of faulkneryne A and diplyne C.