“…[a] D +32.2 (c 0.5,CHCl 3 (d,1 H,J = 7.8 Hz,Ar),7 H,Ar),9 H,Ar),2 H,Ar),2 H,H 1¢ ,H 2¢ ),5.35 (t,1 H,J =9.9 Hz,H 4¢ ),5.26 (m,1 H,H 3 ),5.22 (dd,1 H,J = 9.9,3.1 Hz,H 3¢ ),4.65 (d,1 H,J = 1.5 Hz,H 1 ),4.54 (ddd,1 H,J = 9.9,7.8,3.5 Hz,H 5¢ ),4.35 (dd,1 H,J = 7.8,3.5 Hz,H 6¢a and H 6¢b ),4.20 (m,1 H,H 2 ),4.0 (dt,1 H,J = 9.7,2.8 Hz,H 4 (s,9 H,. 13 C NMR (50 MHz, CDCl 3 ): d = 170.0 (CO),...…”