88292-41-5Relevant academic research and scientific papers
A diastereoselective radical cyclisation approach to pyroglutamates
Goodall, Karen,Parsons, Andrew F.
, p. 491 - 494 (2007/10/03)
The 5-endo radical cyclisation of pyruvic acid derived dehydroalanines which contain chiral ester auxiliaries is reported. Cyclisation of the menthol ester derivative using Bu3SnH at 80°C proceeded with low diastereoselectivity (1.75:1) but the selectivity could be increased to 6:1 on cyclisation of the corresponding 8-phenylmenthyl ester at 20°C.
Asymmetric Reactions of 8-Phenylmenthyl Pyruvate with Allyltrimethylsilane, Silyl Enol Ethers and Ketene Silyl Acetals
Chen, Ming-Yi,Fang, Jim-Min
, p. 1737 - 1742 (2007/10/02)
By mediation of TiCl4, allylsilane, silyl enol ethers and ketene silyl acetals attacked (-)-phenylmenthyl pyruvate and (-)-phenylmenthyl phenylglyoxylate at their si-faces.The reactions are hypothesised to proceed with rigid cyclic transition states: anti aldol adducts 16 and 17a were favourably obtained from E-ketene silyl acetals 6 and 7 having E-configuration, whereas syn aldol adducts 18b-21b were predominantly obtained from Z-ketene silyl acetal 18 and Z-silyl enol ethers 19-21.
