A Divergent Synthesis of Functionalized Unsaturated δ-Lactones from α-Alkenoyl-α-carboxyl Ketene Dithioacetals
作者:Jun Liu、Mang Wang、Bing Li、Qun Liu、Yulong Zhao
DOI:10.1021/jo0702488
日期:2007.6.1
A divergent synthesis of functionalized unsaturated δ-lactones 2, 3, 4, and 5 has been developed starting from the readily available α-alkenoyl-α-carboxyl ketenedithioacetals 1 in high to excellent yields under mild reaction conditions. Thus, 6-substituted 3-(1,3-dithiolan/dithian-2-ylidene)-3H-pyran-2(6H)-ones 2, obtained from a consecutive reduction with NaBH4 and acidic workup of 1 via a novel
Intramolecular Thia-anti-Michael Addition of a Sulfur Anion to Enones: A Regiospecific Approach to Multisubstituted Thiophene Derivatives
作者:Yan Li、Fushun Liang、Xihe Bi、Qun Liu
DOI:10.1021/jo0611420
日期:2006.10.1
The intramolecular thia-anti-Michael addition starting from readily available α-alkenoyl-α‘-carbamoyl ketene-(S,S)-acetals 1 containing a 1,3-dithiolane moiety was developed. In particular, in the presence of aliphatic primary amines, a series of tetrasubstituted thiophene derivatives, 2-(alkylamino)-5-alkyl-4-hydroxythiophene-3-carboxamides 2, were synthesized via tandem fragmentation, substitution
Tandem Thien- and Benzannulations of α-Alkenoyl-α-alkynyl Ketene Dithioacetals with Cyanoacetates: Synthesis of Functionalized Benzo[<i>b</i>]thiophenes
作者:Wenbo Ming、Xiaocui Liu、Lianjie Wang、Jun Liu、Mang Wang
DOI:10.1021/acs.orglett.5b00523
日期:2015.4.3
A novel domino annulation strategy for the construction of benzo[b]thiophenes has been developed. In the presence of Cs2CO3 and Ag2CO3, a wide range of alpha-alkenoyl-alpha-alkynyl ketene dithioacetals readily react with cyanoacetates in CH3CN at 110 degrees C under N-2 to afford multisubstituted benzo[b]thiophenes efficiently via tandem thien- and benzannulations. A plausible mechanism is also proposed.
IODODECARBOXYLATION OF α-CARBOXYLATE, α-CINNAMOYL KETENE CYCLIC DITHIOACETALS
The iododecarboxylation reaction of alpha-carboxylate, alpha-cinnamoyl ketene cyclic dithioacetals 2 was successfully performed with iodine as halogenation reagent and in water insensitive media. This reaction provides a mild and efficient method for the preparation of alpha-iodo, alpha-cinnamoyl ketene cyclic dithioacetals 3 which are important kinds of potential new intermediates to be valued.