Functionalisation of the 4α-methyl group of lanostanol via azidoformate thermolysis

Cytotoxicity and Antiviral Activity of the Compounds fromEuphorbia kansui

“…F-2 (petroleum, 2500-3500m1) was the essential oil. Repeated chromatography of F-3 (petroleum/ acetone, 100:1, 1200-2700m1) by CC (with a gradient of petroleum/acetone) yielded euphol (1, petroleum 100-270m1, 100mg), tirucallol (11) (2, petroleum/acetone 20:1, 96-250 ml, 95mg, [a]°: +4.5° in CHCI3), lanosta-8-en-3J3-ol (12) (3, petroleum/acetone 20: 1, 110-335 ml, 101 mg, [aj5: + 57°in CHCI3), and a mixture of oil (petroelum/acetone 10: 1 124-250 ml). Preparative TLC (silica gel) of the oil with CHCI3 yielded kansuiphorin C (4, R 0.37, 155mg, [a]6: -5.1° in CHCI3) and kansuiphorin D (7) (5, Rf 0.35, 123 mg, [aI6: -58.3°in CHCI3).…”

Thermolysis and photolysis of 3β-lanostenyl azidocarbonate: functionalization of the 4α-methyl group

“…101-103°C) in 30 and 29% yields, respectively, after chromatography and crystallization. Photolysis of cyclohexyl H $sH17 (10) azidocarbonate in CH,Cl, (450 W Hanovia Hg lamp, Pyrex filter, N,) gave a similar result, with (1) and (2) being isolated in 31 and 25O/, yield, respectively. There appears to be no significant preference for the formation of either isomer from the thermal or photochemical reactions in this conformationally tnobile system.…”

Spectroscopic analysis of 3β‐acetoxy‐8‐hydroxy‐8,11‐epoxy‐8,9‐seco‐6,11‐cyclolanostane‐7,9‐dione

“…? 4 Hz) correlation to H-6 (3.16). Analogous one-bond and long-range correlations were taken into consideration for the lateral chain proton and carbon assignments, but these will not be discussed here since the results are consistent with previous assignment for lanosterol derivative ~ide-chains.~…”