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H. Gerlach 《Helvetica chimica acta》1966,49(4):1291-1302
The chirality of the enantiomeric 4-methylcyclohexylideneacetic acids has been determined by a mechanistic correlation with (?)-isoborneol. 相似文献
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Herstellung von erythro-2-Hydroxybernsteinsäure-Derivaten aus Äpfelsäureester. Vorläufige Mitteilung
Preparation for erythro-2-Hydroxy-succinic Acid Derivatives from Malic Esters As a contribution to the much discussed diastereoselective synthesis of enantiomers of open chain compounds, > 90% erythro-selective branching of malic esters by alkylation of the doubly deprotonated derivative 2 (alkoxide-enolate) with methyl, allyl, and benzyl halides in THF at ?78° (→ 3aa, 3ba, 3bb, 3bc , Table 1) is described. A second alkylation (→ 4 ) and addition of 2 to acetone (→ 5 ) are also possible. Cyclization of 2 to the enantiomerically pure trans-epoxides 6 is achieved by treatment with iodine. Cuprate opening of 6b furnishes the same product 3ba obtained from the methylation of 2b , establishing the configurational assignment. 相似文献
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