Carbonylation of alkyltitanium compounds with allylic derivatives
作者:Yasushi Tsuji、Tetsuya Ishii
DOI:10.1016/0022-328x(92)80021-o
日期:1992.2
carbon monoxide (1 atm, balloon) at room temperature overnight (16–18 h), and then the reaction mixture was added to various allyl derivatives in the presence of palladium catalyst (5 mob% based on the allylic derivatives) at room temperature. From 1b and cinnamyl acetate in the presence of tetrakis(triphenylphosphine)palladium, (E)-3,3-dimethyl-6-phenyl-5-hexen-2-one (5a) was afforded in 57% yield. A similar
In the synthesis of the title compound 12, the important intermediate 7 was obtained in good yield from the easily available ethyl 5, 5-ethylenedioxy-2-oxocyclohexane-1-carboxylate (1) via ring enlargement of the bicyclic enol ether 5 (Scheme). Its reduction (NaBH4 in EtOH) and subsequent protection with (t-Bu)Me2Si resulted in the highly functionalized ten-membered lactone 9. Introduction of the (Z)-configurated
Enantioselective synthesis of spiro[4.5]decanone with 2-(S)-methoxy-1,4-dibromobutane
作者:Juan Miguel Garro Galvez、Paul Angers、Persephone Canonne
DOI:10.1016/s0040-4039(00)76641-x
日期:1994.5
The reaction of 3-methyl-2-cyclohexen-1-one with 2-(S)-methoxy-1,4-dibromobutane (2) produced spiro[4.5]decanone 3, a key intermediate for the synthesis of spirovetivanes, with regiodifferentiation and stereoselection. Subsequent addition of diisopropoxydimethyltitanium to the carbonyl group furnished compound 6 with diasterofacial selectivity. The same selectivity was observed in the subsequent catalytic