Enantioselective Phase‐Transfer Catalytic α‐Benzylation and α‐Allylation of α‐tert‐Butoxycarbonyllactones. Issue 4 (22nd February 2013)

• Record Type: Journal Article
• Authors: Ha, Min Woo; Lee, Heejin; Yi, Hye Yeong; Park, Yohan; Kim, Sori; Hong, Suckchang; Lee, Myungmo; Kim, Mi‐hyun; Kim, Taek‐Soo; Park, Hyeung‐geun
• Is Part Of: Advanced synthesis & catalysis. Volume 355:Issue 4(2013)
• Page Start: 637
• Page End: 642
• Publication Date: 2013-02-22
• Subjects: Catalysis -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Chemistry -- Periodicals; Chemistry, Technical -- Periodicals; Chemistry -- Periodicals; Catalysis -- Periodicals; Technology, Pharmaceutical -- Periodicals; 547.2
• DOI: 10.1002/adsc.201200976
• Languages: English
• ISSNs: 1615-4150

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A new enantioselective α‐benzylation and α‐allylation of α‐<italic>tert</italic>‐butoxycarbonyllactones was devloped. α‐Benzylation and α‐allylation of α‐<italic>tert</italic>‐butoxycarbonylbutyrolactone and α‐<italic>tert</italic>‐butoxycarbonylvalerolactone under phase‐transfer catalytic conditions (50% cesium hydroxide, toluene, −60 °C) in the presence of (<italic>S</italic>, <italic>S</italic>)‐3, 4, 5‐trifluorophenyl‐NAS bromide (1 mol%) afforded the corresponding α‐substituted α‐<italic>tert</italic>‐butoxycarbonyllactones in very high chemical yields (up to 99%) and optical yields (up to 99% <italic>ee</italic>). The synthetic potential of this method has been successfully demonstrated by the asymmetric synthesis of unnatural α‐quaternary homoserines, 3‐alkyl‐3‐carboxypyrrolidine and 3‐alkyl‐3‐carboxypiperidine.</p> </abstract>