| abstract |
A compound has the formula n nin racemic form, enantiomerically enriched form or enantiomerically pure form. R 6 is preferably —Si(R 8 R 9 R 10 ) or —(R 7 )Si(R 8 R 9 R 10 ), wherein R 7 is an alkylene group, an alkenylene group, or an alkynylene group; and R 8 , R 9 and R 10 are independently a C 1-10 alkyl group, a C 2-10 alkenyl group, a C 2-10 alkynyl group, an aryl group or a —(CH 2 ) N R 11 group, wherein N is an integer within the range of 1 through 10 and R 11 is a hydroxy group, alkoxy group, an amino group, an alkylamino group, a dialkylamino group, a halogen atom, a cyano group, —SR c or a nitro group. R 1–R 4 can be broadly substituted. R 5 is preferably a C 1-10 alkyl group, an alkenyl group, an alkynyl group, or a benzyl group. R 13 is preferably H, F or —CH 3 . R 16 is R 16 is —C(O)R f or H. The E-ring (the lactone ring) may be opened. A method of synthesis of compound (1) and intermediates in the synthesis thereof are provided. |