Sly1 enol ethers of ketones are alkylated with ethyl a-chloro-a-phenylseleno acetate la or with ethyl a-chloro-a-phenylseleno propionate lb, mediated by zinc bromide to give the corresponding a-phenylseleno-y-keto esters 3 in moderate to good yields.
A regiospecific synthesis of γ-keto esters: the alkylation of o-silylated enolates with methyl α-chloro- α-phenylthioacetate
✍ Scribed by Thomas V. Lee; Jonathan O. Okonkwo
- Publisher
- Elsevier Science
- Year
- 1983
- Tongue
- French
- Weight
- 153 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0040-4039
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📜 SIMILAR VOLUMES
O-Silylated ketone enolates can be alkylated regiospecifically with t-alkyl halides in the presence of an equivalent of titanium tetrachloride; 2 for the alkylation of lithium enolates, in general, dialkylation,3 loss of regiospecificity,3 and self-condensation4 are common problems. Alternative me
Treatment of lithium ester enolates with magnesium alkylidene carbenoids, generated from 1-chlorovinyl p-tolyl sulfoxides with isopropylmagnesium chloride via the sulfoxide-magnesium exchange reaction, gave b,c-unsaturated esters in moderate to good yields. When this reaction was conducted with the
## Abstract The __C__ methylation of the carbohydrate‐derived __O__‐chiral esters 5a‐d to derivatives 8 proceeds with (__R__) selection of 1:1 to 10:1 and depends primarily on the base used for enolate generation. Lithium 2,2,6,6‐tetramethylpiperide (LTMP) shows the highest and lithium hexamethyldi