| 摘要 |
<p>Compounds and a method of synthesis of compounds of formula (Ia) or (Ib): and salts, solvates, and chemically protected forms thereof, wherein the dotted lines indicate the optional presence of a double bond between C1 and C2 or C2 and C3; R2 and R3 are independently selected from -H, -O, -CH2, -CN, -R, OR, halo, -CH-R, O-SO2-R, CO2R and COR; R10 is a carbamate-based nitrogen protecting group; and R11 is an oxygen protecting group.</p> |
