A new general one-pot method for high-yield synthesis of S-alkyl β-ketothioesters by heating of 6-mono- and 5, 6-disubstituted 1, 3-dioxin-4-ones and thiols in an appropriate aprotic solvent is described. This procedure is available for large-scale preparation of a variety of β-ketothioesters.
Practical Synthesis of β-Ketothioesters by Acid-Catalyzed Hydrolysis of Ketene <i>N,S</i>
-Acetals with Amino as the Leaving Group
作者:Qi Xu、Baihui Zheng、Ling Pan、Qun Liu、Yifei Li
DOI:10.1002/ejoc.201900634
日期:2019.6.16
β‐ketothioesters from α‐oxo ketene N,S‐acetals has been developed. In this acid‐catalyzed reaction, the amino group, including both alkylamino and arylamino groups, of ketene N,S‐acetals can be easily displaced in the presence of H2O as nucleophile (hydrolysis) instead of the alkylthiol group reported.
Selective Catalytic Transesterification, Transthiolesterification, and Protection of Carbonyl Compounds over Natural Kaolinitic Clay
作者:Datta E. Ponde、Vishnu H. Deshpande、Vivek J. Bulbule、Arumugam Sudalai、Anil S.Gajare
DOI:10.1021/jo971404l
日期:1998.2.1
Transesterification and transthiolesterification of beta-keto esters with variety of alcohols and thiols and selective protection of carbonyl functions with various protecting groups catalyzed by natural kaolinitic clay are described. The clay has been found to be an efficient catalyst in transesterifying long chain alcohols, unsaturated alcohols, and phenols to give their corresponding beta-keto esters in high yields. For the first time, transthiolesterification of beta-keto esters with a variety of thiols has been achieved under catalytic conditions. Clay also catalyzes selective transesterification of beta-keto esters by primary alcohols in the presence of secondary and tertiary alcohols giving corresponding beta-keto esters. A systematic study involving the reactivity of different nucleophiles (alcohols, amines, and thiols) toward beta-keto esters is also described. Sterically hindered carbonyl groups as well as alpha,beta-unsaturated carbonyl groups underwent protection without the deconjugation of the double bond. Chemoselective protection of aldehydes in the presence of ketones has also been achieved over natural kaolinitic clay.
Andreichikov, Yu. S.; Tendryakova, S. P.; Nalimova, Yu. A., Journal of Organic Chemistry USSR (English Translation), 1982, p. 171 - 175
作者:Andreichikov, Yu. S.、Tendryakova, S. P.、Nalimova, Yu. A.、Krylova, I. V.
DOI:——
日期:——
SAKAKI, JUN-ICHI;KOBAYASHI, SATOSHI;SATO, MASAYUKI;KANEKO, CHIKARA, CHEM. AND PHARM. BULL., 38,(1990) N, C. 2262-2264