“…It was recrystallised from dichloromethane-diethyl ether-hexane to give (5aR,6aS,7R,lOaS, 1 1aS)-5a,l la-epoxy-5a,6a,7,10,lOa,l la-hexahydro-7-[( 2 (6 600), and 307 nm (2 400); 6(300 MHz; CDCl,) 0.30 (9 H,s,SiMe,),1.84,1.96,1.97,and 2.18 (each 3 H,s,together 4 x MeCO), 2.72br (1 H, d, J 18 Hz, lO-H,),3.16(1 H,dd,J7and4Hz,6a-H),3.60(1 H,ddd,J9.5,5, and 2. 5 Hz,3.76br (1 H, t, J 6.5 and 6.5 Hz, 10a-H), 4.14 (1 H,dd,J 12 and 5 Hz,4.26 (1 H,dd,J 12 and 2.5 Hz,6'-H), 4.42 (1 H,d,J 8 Hz,4.57 (1 H,dd,J9.5 and 8 Hz,4.93 (1 H,t,J9.5 and 9.5 Hz,4.94 (1 H,dd,J 6 and 4.5 Hz,4.98(1 H,d,J6Hz,8-H),5.11(1H,t,J9.5and9.5Hzy3'-H), 7.75-7.85, 8.02-8.07, and 8.12-8.17 (2, 1, and 1 H, each m, together 1-, 2-, 3-, and 4-H) (the signal for 10-H, was partly obscured by the signal at 6 2.18); m/z (c.i.) 542 (30%), 541 (3373, 450 (2273, 379 (5773, 378 (5473, and 331 (100%) (Found: C, 56.7; H, 4.9.…”