... 29 (1981) 3.42 (2H, t, j=7 Hz, 1'—H2), 2.62 (3H, s, 2-Me), 5.1-6.4 (7H, m, olefinic protons), 5.7 (1H, br, NH), 1.26 and 4.19 (3H, t, and 2H, q, COzEt), Anal ... 16) A part of this work has been published in a preliminary communication: T. Tsuchiya and H. Sashida, Heterooyeles, 12 ...