Solvolytic rearrangement of the 2-(Δ1-cyclopentenyl)ethyl system
作者:W.D. Closson、G.T. Kwiatkowski
DOI:10.1016/s0040-4020(01)98363-2
日期:1965.1
2-(Δ1-cyclopentenyl)ethyl bromobenzenesulfonate (I) yields four rearranged acetates. The major product is 3-methylenecyclohexyl acetate, while spiro[2.4]heptan-4-yl, bicyclo[3.2.0]heptan-1-yl, and bicyclo[3.1.0]hexane-1-methyl acetate are produced in smaller amounts. Consideration of the solvolytic reactions of derivatives possessing these rearranged structures allows presentation of an overall scheme of reaction
Rhodium-Catalyzed Ring Expansion of Cyclopropanes to Seven-membered Rings by 1,5 CC Bond Migration
作者:Xiaoxun Li、Min Zhang、Dongxu Shu、Patrick J. Robichaux、Suyu Huang、Weiping Tang
DOI:10.1002/anie.201104861
日期:2011.10.24
of rhodium: Highly functionalized seven‐membered rings were prepared from substitutedcyclopropanes by a RhI‐catalyzed tandem isomerization reaction. The π‐acidic RhI catalyst promoted the formation of an allene intermediate by a 1,3 acyloxy migration of a propargyl ester and a subsequent net 1,5 migration of a cyclopropane CC bond.
1-Alkylamino-3-(5-carbocyclicalkylaminocarbonylthiazol-2-yloxy)-2-propanol; 5-(5-carbocyclicalkylaminocarbonylthiazol-2-yloxymethylene-N-alkyloxazolid ine and/or 2-substituted oxazolidine derivatives thereof, and methods of making such compounds. The compounds exhibit cardiovascular activity and are useful in the treatment of abnormal heart conditions in mammals. The compounds are also useful in the treatment of hypertension in mammals. The 5-(5-carbocyclicalkylaminocarbonylthiazol-2-yloxymethylene)-N-alkyloxazoli dines and derivatives are also intermediates for the 1-alkylamino-3-(5-carbocyclicalkylaminocarbonylthiazol-2-yloxy)-2-propanol s. The 1-alkylamino-3-(5-carbocyclicalkylaminocarbonylthiazol-2-yloxy)-2-propanol s can be prepared by base or acid hydrolysis of the corresponding 5-(5-carbocyclicalkylaminocarbonylthiazol-2-yloxymethylene)-N-alkyloxazoli dine or derivative; or by treatment of the corresponding 3-(5-carbocyclicalkylaminocarbonylthiazol-2-yloxy)-2,3-epoxypropane with the desired alkylamine. Similarly the 5-(5-carbocyclicalkylaminocarbonylthiazol-2-yloxymethylene)-N-alkyloxazoli dine or derivative can be prepared from the corresponding 1-alkylamino-3-(5-carbocyclicalkylaminocarbonylthiazol-2-yloxy)-2-propanol s via treatment with an aldehyde or ketone.
1,3-Elimination reactions of (3,4-epoxybutyl)stannanes. Approach to the synthesis of cycloeudesmol
作者:Louis Plamondon、James D. Wuest
DOI:10.1021/jo00006a019
日期:1991.3
The reactions that occur when stereochemically defined spirocyclic (3,4-epoxybutyl)stannanes are treated with C2H5AlCl2 depend critically on the relative orientation of tin, oxygen, and the three connecting atoms of carbon. A W arrangement of these atoms tends to favor formation of cyclopropanes by a concerted 1,3-elimination with inversion at both carbon centers. If this orientation cannot be achieved, cleavage of the epoxide occurs to give an ionic intermediate that can undergo a subsequent 1,3-elimination or a 1,2-shift of hydride promoted by an antiperiplanar carbon-tin bond.
RAZUS, ALEXANDRU C.;GHEORGHIU, MIRCEA D.;BARTHA, EMERIC, REV. ROUM. CHIM., 34,(1989) N1-12, C. 2075-2086
作者:RAZUS, ALEXANDRU C.、GHEORGHIU, MIRCEA D.、BARTHA, EMERIC