Macrolactonization Yamaguchi

This material is converted to bryostatin 1 in 11 steps, including Yamaguchi macrolactonization, installation of the B-ring enoate using Fuji s chiral phosphonate [38] and, remarkably, selective hydrolysis of the C20 acetate in the presence of Cl-macrolide, C7 acetate, as well as the Cl3 and C21 enoate moieties (Scheme 5.6). 

Related reactions Keck macrolactonization, Yamaguchi macrolactonization ... 

Recently, Shishido has achieved the third total synthesis of (+)-lasonolide A, and their synthetic strategy was based on the introduction of the side chain via Lee s protocol, the successful Yamaguchi macrolactonization, and the... 

After installation of the C1-C4 unit, the Yamaguchi macrolactonization [60] was subjected to the seco-acid derived from 113 to successfully yield the macrolactone 114, although Kang s group failed. Finally, the side chain was introduced to the macrolactone via Lee s method to provide (+)-lasonolide A. 

The synthetic strategy is based on Yamaguchi macrolactonization, metal alkynylide addition at C17, Mukaiyama-aldol Prins reaction of vinyl ether 219 with aldehyde 218 forming 2,6-d5-tetrahydropyran, Hosomi-Sakurai reaction giving 2,6-tran5-tetrahydropyran, asymmetric center formation via Myers alkylation at C12 and Noyori reduction at C15 and C3 (Scheme 47). 

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