Cm. Hayward et al., AN APPLICATION OF THE SUAREZ REACTION TO THE REGIOSPECIFIC AND STEREOSPECIFIC SYNTHESIS OF THE C-28-C-42 SEGMENT OF RAPAMYCIN, Tetrahedron letters, 34(25), 1993, pp. 3989-3992
Specific lactonization of a TBS ether followed by iodinative scisson o
f a gamma-lactol are the key elements of a strategy for maintaining co
ntinuous chemical distinction between the latent C34 and C32 hydroxyl
groups of starting material 3 en route to 14, the C28-C42 fragment of
rapamycin.