Patent ID: 7691802

Claim:
A compound of formula I wherein R 1 , R 4 , R 6 and R 7 are independently hydrogen, methyl or ethyl; R 2 and R 3 are independently hydrogen, or C 1-5 alkyl; or R 2 and R 3 together with the carbon atom to which they are attached form a 5- or 6-membered cycloylkyl ring; R 5 is hydrogen, or C 1-4 alkyl; R 8 is hydrogen, or branched lower C 3-7 alkyl; R 9 is hydrogen, methyl, ethyl, or branched lower C 3-7 alkyl; R 10 is ethyl or propyl; R 11 is C 1-4 alkyl; R 12 is hydroxy; R 13 is hydrogen, or C 1-4 alkyl; or R 12 and R 13 together with the carbon atom to which they are attached form a carbonyl group; the dashed line represents either a C—C single bond or no bond; and a) when C5 and C8 are connected by a single bond and C9 and C6 are connected by a single bond, C9 and C5 are not connected by a bond, n=1, R 7 , R 8 are hydrogen, and R 9 is hydrogen, methyl or ethyl; or b) when C5 and C8 are connected by a single bond and C9 and C6 are connected by a single bond, C9 and C5 are not connected, n=0, R 7 , R 8 is hydrogen, R 9 is a branched lower C 3-7 alkyl; or c) when C5 and C8 are not connected by a bond, C9 and C5 are connected by a single bond, R 7 is hydrogen, methyl or ethyl, R 8 is a branched lower C 3-7 alkyl, or R 7 and R 8 together with the carbon atoms to which they are attached form a 5- or 6-membered cycloalkyl ring, n=0, and the bond between C6 and C8 may be a single bond or a double bond.