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Stereoselective synthesis of β-hydroxy-α-methylcarboxylic acid thiol esters via vinyloxyboranes

✍ Scribed by Masahiro Hirama; Satoru Masamune

Publisher
Elsevier Science
Year
1979
Tongue
French
Weight
199 KB
Volume
20
Category
Article
ISSN
0040-4039

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✦ Synopsis

Both threo-and erythro-8-hydroxy-u-methylcarboxylic acid thiol esters are stereoselectively synthesized through an aldol-type condensation of vinyloxyboranes derived formally from S-tertbutyl propanethioate.

The basic carbon skeletons of many macrolide antibiotics are biosynthesized through a series of condensations of acetyl-and propionyl-CoA units and are rich in chirality. 1 Methods to achieve stereoselective construction of the @hydroxy-a-methylcarbonyl system, 2 therefore, are highly useful for, and sometimes essential to, the synthesis of these antibiotics.

We have recently demonstrated that z-and E-vinyloxyboranes can be prepared stereoselectively and that the z-and s-isomers react with aldehydes to yield mainly the erythro and threo aldol products, ~-

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