- 作者: Ernest L. Eliel, Xu Bai and Masaki Ohwa
- 中文摘要:
The previously described chiral 2-acyloxathianes 5(Scheme I) are used in two different enantioselective syntheses of g-butyrolactones. In one synthesis, Grignard addition, cleavage and reduction to carbinols RR'C(OH)CH2OH is followed by tosylation, malonate homologation, lactonization, and removal of the carbomethoxy group to give optically active g-lactones. A modification of this synthesis (Scheme I) leads to optically active a-methylene-g-lactones.
In the second synthesis, reaction of a bromomagnesium enolate with ketones 5 leads to b-hydroxyesters, which, by appropriate sequences of reduction and cleavage (Scheme II) are converted to optically active a- or b-hydroxy-g-lactones. - 英文摘要: --
- 中文關鍵字: --
- 英文關鍵字: --