... Compounds 5-7 were lormed in yields of 18, 22, and 57% respectively under the usual ... ND Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913; e-mail: lb@ l ... 6H, s, 2CH,); 6.88 ppm (2H, s, H.,.,) The 'H NMR spectrum given for compound 6 in ...