conditions in the absence of Pd catalysis. The power of this modified Stille protocol
was elegantly applied to the total synthesis of elaiolide 129 [81] (Scheme 33). Thus,
treatment of a 10 mM solution of monomer 127, in N-methylpyrrolidinone with
CuTC (10 equivalent) at ambient temperature for 15 min, produced the required
16-membered macrocycle 128 as a white crystalline solid in excellent yield.
10 Macrolactonization Through Intramolecular
Nozaki–Hiyama–Kishi Coupling
The Nozaki–Hiyama–Kishi (NHK) coupling strategy has its advantages in joining
vinyl halides directly to aldehydes. The major disadvantage using this protocol
is the low level of stereocontrol of the newly formed secondary alcohol. Consequently, a significant number of applications used this disconnection at positions
were the so-generated alcohol has to be oxidized later on.
Scheme 32 Intramolecular Stille coupling using polymer bound Pd(0) catalyst Pd(PPh 3 ) 4 in the
total synthesis of (S)-zearalenone, 126
Scheme 33 Rapid intramolecular Stille cross coupling applying the Allred and Liebeskind
protocol
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M. Cordes and M. Kalesse
was elegantly applied to the total synthesis of elaiolide 129 [81] (Scheme 33). Thus,
treatment of a 10 mM solution of monomer 127, in N-methylpyrrolidinone with
CuTC (10 equivalent) at ambient temperature for 15 min, produced the required
16-membered macrocycle 128 as a white crystalline solid in excellent yield.
10 Macrolactonization Through Intramolecular
Nozaki–Hiyama–Kishi Coupling
The Nozaki–Hiyama–Kishi (NHK) coupling strategy has its advantages in joining
vinyl halides directly to aldehydes. The major disadvantage using this protocol
is the low level of stereocontrol of the newly formed secondary alcohol. Consequently, a significant number of applications used this disconnection at positions
were the so-generated alcohol has to be oxidized later on.
Scheme 32 Intramolecular Stille coupling using polymer bound Pd(0) catalyst Pd(PPh 3 ) 4 in the
total synthesis of (S)-zearalenone, 126
Scheme 33 Rapid intramolecular Stille cross coupling applying the Allred and Liebeskind
protocol
396
M. Cordes and M. Kalesse