A New Entry to Oxacycles via Base-Catalyzed Endo Mode Cyclization of Allenyl Sulfoxides and Sulfones
摘要:
[GRAPHICS]Treatment of the allenyl sulfoxides and sulfones possessing a proper delta -hydroxy appendage at the C-1 position with potassium tert-butoxide effected endo mode ring closure at the sp-hybridized carbon center of the allenyl moiety to provide the five- to eight-membered oxacycles in high yields.
Hydrogenation Promoter, Hydrogenation Catalyst, and Process for Producing Alkene Compound
申请人:Hori Junichi
公开号:US20080033221A1
公开(公告)日:2008-02-07
A hydrogenation promoter of the present invention is produced by reacting an alkyne compound or an alkene compound, a palladium compound represented by a general formula Pd(II)X
j
L
k
(where L represents a monodentate ligand or a polydendate ligand other than a phosphorus-containing ligand (when two or more Ls are present in the compound, the Ls may be the same or different), X represents an anionic group, j represents a value determined according to the valence of X so that X
j
has a valence of −2 as a whole, and k represents an integer in the range of 0 to 4), and a base in an organic solvent. Specifically, The hydrogenation promoter of the invention includes palladium nanoparticles containing the alkyne compound or the alkene compound as an agglomeration-preventing agent.
A reliable and efficient procedure for constructing five- to eight-membered oxacycles has been developed. Allenes with both a phosphoryl group and a suitable delta-hydroxyalkyl side chain at the Cl-position underwent an endo mode ring-closing reaction to give five- to seven-membered oxacycles. Changing the phosphoryl group to a phosphono functionality facilitated the preparation of eight-membered congeners. Introduction of a cis double bond to the alkyl side chain of the starting allenes made possible the easy formation of medium-sized oxacycles, such as the dihydrooxocin and tetrahydrooxonin frameworks, regardless of the electron-withdrawing group (POPh2, PO(OEt)(2), SOPh, and SO2Ph) at the C-1-position.
KLOK R.; MOEHLMANN W. M. M.; WOLF L.; PABON H. J. J., REC. TRAV. CHIM. PAYS-BAS, 1980, 99, NO 4, 132-137
作者:KLOK R.、 MOEHLMANN W. M. M.、 WOLF L.、 PABON H. J. J.
DOI:——
日期:——
US7619125B2
申请人:——
公开号:US7619125B2
公开(公告)日:2009-11-17
A New Entry to Oxacycles via Base-Catalyzed Endo Mode Cyclization of Allenyl Sulfoxides and Sulfones
[GRAPHICS]Treatment of the allenyl sulfoxides and sulfones possessing a proper delta -hydroxy appendage at the C-1 position with potassium tert-butoxide effected endo mode ring closure at the sp-hybridized carbon center of the allenyl moiety to provide the five- to eight-membered oxacycles in high yields.