(3R,4R,5R,8R,9R,10R,13S,14R,15S)-3-(1-Hydroxymethyl-vinyl)-15-isopropyl-4-(2-methoxycarbonyl-ethyl)-4,9,10-trimethyl-hexadecahydro-cyclopenta[a]phenanthrene-13-carboxylic acid methyl ester