toluene-4-sulfonic acid in dichloromethane T=0°C; 1.25 h;
参考文献
Fox, Martin E.; Holmes, Andrew B.; Forbes, Ian T.; Thompson, Mervyn
Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1994 , # 23 p. 3379 - 3396
Moody, Christopher J.; Shah, Pritom; Knowles, Philip
Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1988 , p. 3249 - 3254